Best drain unblockers for kitchen sinks, showers and baths

We've tested popular drain unblockers from Mr Muscle, HG and Buster to see which clears blockages the quickest. 

We got our hands dirty testing kitchen and bathroom drain unblockers against the worst a house has to offer. Whether it's removing greasy food build-up or clumps of tangled hair, we found the products that can tackle the most stubborn clogs.

We also put a common home remedy of bicarbonate of soda, salt and vinegar to the test.

Just Buy This 

Don't want to shop around? If you're after an unblocker that can handle everything from kitchen grease to a hair-clogged shower, this is the only bottle you need.

Mr Muscle Power Gel Drain Unblocker - Best Buy & Great Value

Mr Muscle Power Gel is the only unblocker to get a Best Buy recommendation for both bathroom and kitchen drains, making it the ultimate all-rounder. 

It set the bar high in our kitchen tests, dealing with greasy food clogs in just five minutes - three times faster than the other drain unblockers we tested. It’s just as tough in the shower, dissolving stubborn hairballs in 20 minutes flat. 

And at only £5 a bottle, it also earned our Great Value recommendation. Keep a bottle under your sink and you'll be covered for any drain disaster.

Available from Asda (£2.74), Sainsbury's, Tesco (£4.25), Amazon (£4.50 x2), Ocado (£4.50), Waitrose (£4.65)

Wondering how soda crystals and other drain unblockers compared? See our test results below. 

The best shower drain unblockers from our tests

While every unblocker eventually worked, some lagged hours behind the best. The Buster Bathroom Plughole Unblocker was the fastest, dissolving hair and soap scum in just 15 minutes. Alongside Mr Muscle, it's a Best Buy; and because you get plenty of liquid for the price, they’re both Great Value recommendations, too.

As with any bleach-based products, make sure you always wear gloves, old clothes and follow the instructions carefully. 

The products below are suitable for shower blockages. If you want to unblock a drain clogged with food, take a look at our pick of the best kitchen drain unblockers.

Compare results and prices of the shower drain unblockers we've tested in the table below.

Best Buy/Great Value: Buster Bathroom Plughole Unblocker

Our verdict Our top shower drain unblocker

Available from Waitrose (£3), Morrisons, Ocado, Sainsbury's, Wilko (£4)

Pros

• Clears the pipes
• Worked in 15 minutes
• Easy-to-read instructions

Cons

• Single-use plastic bottle 

Size 300ml

Speed to unblock drain 15 minutes

Suitable for a septic tank Yes

Buster Bathroom Plughole Unblocker proved itself a worthy Best Buy with its fast-acting cleaning power. 

The two large hairballs we'd made from a combination of different types of tangled hair were shrunk down and able to pass through the U-bend without further issue during our tests.  

 Best Buy/Great Value: Mr Muscle Power Gel Drain Unblocker

Our verdict Very fast-acting and effective

Available from Asda (£2.74), Sainsbury's, Tesco (£4.25), Amazon (£4.50 x2), Ocado (£4.50), Waitrose (£4.65)

Pros

• Clears the pipes
• Works on hair within 20 minutes

Cons

• With the smaller size it is single-use per bottle

Size 500ml, also comes in 1 litre

Speed to unblock drain 20 minutes

Suitable for a septic tank Yes 

Due to the stubborn nature of a hairball clog, we allowed Mr Muscle Power Gel Drain Unblocker 20 minutes during our tests, as the instructions state to leave it for longer for tough clogs.

However, we found it seemed to work even faster than that. 

See how long it took to dissolve a greasy food blockage in our kitchen drain unblocker tests below.

Want sparkling bathroom and kitchen surfaces? Check out the best cleaning sprays

 HG Hair Unblocker

Our verdict Great, but takes up some space

Available from Ocado, Tesco (£8.50), B&Q (£8), Homebase (£5.99)

Pros

• Clears the pipes
• Instructions are clear and easy to follow

Cons

• Single-use bottle
• The product is two plastic bottles in a cardboard box

Size 450ml

Speed to unblock drain 1 hour

Suitable for a septic tank No

HG Hair Unblocker is made up of two bottles that you pour into your drain one at a time, so it comes with a lot of packaging.

It takes around an hour for the unblocker to work, and the hairballs then flushed through our U-bend in our tests. 

Flexisnake

Our verdict Chemical-free and fast

Available from Lakeland (£9.99)

Pros

• Reusable
• Quick and easy to use

Cons

• Hard to clean
• A bit messy

Length 45.72 cm

Speed to unblock drain Within minutes

Suitable for a septic tank Yes

We tested The Drain Millipede flexisnake. You can no longer buy that exact brand, but plenty of other very similar products are available that do the same thing. 

A flexisnake is a reusable, chemical-free option that is ideal for eco-conscious households wanting to avoid chemicals. 

Those with more crude tastes may find a simple joy in extricating hair clogs from the plughole with this type of unblocker. 

For others, this process may be somewhat gross. Either way, this tool is easy to use and effective. 

 Ecozone Plughole Hair Unblocker

Our verdict Slow and somewhat pungent

Available from Ecozone Direct (£8.65), Amazon (£9.99), Ocado (£8)

Pros

• Two uses per bottle
• Simple and easy-to-read instructions

Cons

• Required a plunger to get rid of the hairball
• Creates a strong and unpleasant scent
• Takes 12 hours

Size 250 ml

Speed to unblock drain 12 hours

Suitable for a septic tank Yes

This unblocker needed 12 hours to work and during that time the area around the sink had an unpleasant burnt hair smell. 

After the 12 hours had passed, the hairball was removed with the aid of a plunger.

 Bathroom Blocks Away Plughole Unblocker

Our verdict Slow and ineffective

Available from Lakeland (£4.99)

Pros

• Two uses per bottle

Cons

• Required a plunger to get rid of the hairball
• Creates an overpowering scent
• Takes at least six hours

Size 250ml

Speed to unblock drain 6 hours

Suitable for a septic tank Yes

We still needed a plunger to dislodge the hairball after waiting for the unblocker to work overnight.

It also creates a very pungent and lingering smell of burnt hair. 

Between the wait time, the stench and how it needed extra help, we weren't impressed with this unblocker. 

Soda Crystals

Our verdict Ineffective at removing hair

Pros

• Can be used for other cleaning chores

Cons

• Required a plunger
• Seemed to make no difference to the hairball
• Requires more preparation than the others

Size 1kg

Speed to unblock drain 30 minutes

Suitable for a septic tank Yes

Soda crystals have many uses, but removing hair from a shower's plughole doesn't seem to be one of them. 

They seemed to do nothing to the hairballs during our tests. We were left having to unclog the sink with a plunger.

See if soda crystals dissolved grease and food in our kitchen drain unblocker tests below. 

The best kitchen drain unblockers from our tests

All the kitchen drain unblockers we tested work. However, our top pick and only Best Buy, the Mr Muscle Power Gel Drain Unblocker, was by the far the fastest at dissolving stubborn food residue and grease in a blocked U-bend. 

The products below are suitable for food blockages. If you want to unblock a drain clogged with hair, take a look at the best shower drain unblockers.

Most drain unblockers are bleach-based, so make sure you follow the instructions carefully and wear gloves and old clothes. If you want to give a home remedy a go, see how our test of bicarbonate of soda, salt and vinegar compared.

Compare results and prices of the kitchen drain unblockers we've tested in the table below.

Best Buy: Mr Muscle Power Gel Drain Unblocker

Our verdict Our top kitchen drain unblocker

Available from Asda (£2.74), Sainsbury's, Tesco (£4.25) Amazon (£3.99)

Pros

• Clears the pipes
• Works super quickly

Cons

• In the smaller size it's a single-use plastic bottle

Size 500ml, also comes in 1 litre

Speed to unblock drain Five minutes

Suitable for a septic tank Yes

All the drain unblockers tested worked (although some needed a bit of extra help), but Mr Muscle Power Gel was easily the fastest. 

Within five minutes the clogs in our drain were dissolved. 

If getting the job done fast is what's important to you, then keep a bottle of this under your sink. 

See how it performed in our tougher shower drain unblocker tests.

Sainsbury's Sink & Plughole Unblocker

Our verdict Good results with a quick turnaround

Available from Sainsbury's (£2.25)

Pros

• Clears the pipes
• Works quickly

Cons

• Single-use bottle

Size 500ml

Speed to unblock drain 15 minutes

Suitable for a septic tank Yes

It only took 15 minutes for this plughole unblocker from Sainsbury's to cut through the grease and food residue. 

Once it had finished, the pipes and U-bend were squeaky clean.

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Essential Waitrose & Partners Drain Unblocker

Our verdict Fast-acting with consistent results

Available from Waitrose (£2.45)

Pros

• Clears the pipes
• Works quickly

Cons

• Single-use plastic bottle

Size 500ml

Speed to unblock drain 15 minutes

Suitable for a septic tank No

Like many of the other bleach-based products, this unblocker from Waitrose & Partners quickly dealt with the clog. 

Cillit Bang Drain Odour Eliminator & Unblocker Gel

Our verdict Decent

Available from Wilko (£2.59), Ocado (£2.60), Amazon (£11.99 x 3)

Pros

• Clears the pipes

Cons

• Single-use bottle

Size 500ml

Speed to unblock drain 30 minutes

Suitable for a septic tank The manufacturer says they are unable to test on all septic tanks. Therefore, it's safest for you to check with your septic tank provider. 

This unblocker gel from Cillit Bang was not the fastest, but it was by no means the slowest product we tested. 

It effectively removed the clogs in our tests.

Soda Crystals 

Our verdict Effective but requires preparation

Pros

• Clears the pipes
• Offers lots of cleaning options

Cons

• Requires more preparation than the others

Size 1kg

Speed to unblock drain 30 minutes

Suitable for a septic tank Yes

Soda crystals worked, but are a faff to use compared with the other products we tested. 

You need to prepare the solution first, then pour it down the drain. We tested it twice, and the blockage was removed within 30 minutes on both occasions.

On the plus side, Soda crystals are a very affordable product with a lot of cleaning utility - you can use them to clean your washing machine, barbecue, pots and pans, as well as remove stains on clothes and fabrics.

See how soda crystals coped with clogged hair in our shower drain unblocker tests. 

 HG Kitchen Drain Unblocker

Our verdict Slower than most 

Pros

• Clears the pipes

Cons

• Slowly unblocks
• No child safety cap (although it's not required by law to have one)

Size 1 litre

Speed to unblock drain Up to six hours

Suitable for a septic tank Yes

You get more for your money, but this product isn't as simple as just pouring and leaving as you need to mix it with water.

It takes a minimum of six hours to work, but if you're happy to wait or leave it overnight, this could be the one for you. 

Ecozone Kitchen Drain Unblocker

Our verdict Eventually does the job

Available from Amazon (£9.99)

Pros

• Clears the pipes
• Doesn't have too strong a scent

Cons

• Slowly unblocks
• No child safety cap (although it's not required by law to have one)

Size 1 litre

Speed to unblock drain Up to 12 hours

Suitable for a septic tank Yes

During our tests, the Ecozone Kitchen Drain Unblocker managed to remove the clog from our pipes but it took a very long time. 

However, this might not be an issue if you use it in the evening and leave it overnight. 

Tesco Sink & Drain Unblocker

Our verdict A speedy solution to a blocked drain

Available from Tesco (£2.25)

Pros

• Clears the pipes
• Works quickly

Cons

• Single-use plastic bottle

Size 500ml

Speed to unblock drain 15 minutes

Suitable for a septic tank Waiting for a response from the manufacturer

After 15 minutes, the Tesco Sink & Drain Unblocker had done its job and removed the clog from our U-bend.

Buster Kitchen Plughole Unblocker

Our verdict Left behind a new blockage

Pros

• Doesn't leave a lingering scent

Cons

• We needed a plunger to completely remove the blockage
• Single-use plastic bottle

Size 200g

Speed to unblock drain 20 minutes

Suitable for a septic tank Yes

Buster Kitchen Plughole Unblocker dissolved the clogs into a greasy acidic sludge that created a new blockage. However, this second clog was easily flushed away with a single strike of our plunger. 

We were much more impressed by Buster Bathroom Plughole Unblocker.

When you use this product, don't leave it in the pipes for more than 20 minutes, make sure you wear gloves, don't get any on your skin and open all the windows in the room. 

How we test drain unblockers

We buy the bestselling drain unblockers and put them through our tough tests. We don't accept freebies from product manufacturers or retailers.

The setup

We use a freestanding catering sink for our tests, swapping in a fresh 44mm U-bend for every product we review.

To simulate the worst-case scenarios you actually face at home, we create two types of blockages:

• For kitchen drain unblockers: A mixture of equal parts grated broccoli, melted lard and breadcrumbs. 
• For shower drain unblockers: A hairball made of equal parts straight, wavy and curly human hair mixed with shampoo. 

To ensure each clog is firmly lodged in place, 500ml of boiling water is poured into the plughole before the test begins.

The unblockers are then applied following their instructions and left for the minimum required time. 

Afterwards, the U-bends are flushed through with eight litres of hot tap water. If necessary, a plunger is used at this point. We've noted above when a plunger is needed.

The test

• The pipes are examined with a tube camera before and after the products are applied, to see how effectively they work.

• Then we time how long it takes for eight litres of cold tap water to pass through the U-bend and pipes. 

• We compare these timings to a test done on an unused U-bend. The quicker the water passes through, the better - it shows the unblocker has worked. Each product is tested twice. 

Why you can trust us: at Which? we're free from manufacturer and retailer influence. Find out more about our impartiality and how your support helps us to stay editorially independent.

How to unblock a drain 

• As most drain unblockers are bleach-based, we recommend wearing rubber gloves over a long-sleeved top for your protection. Make sure it's an old piece of clothing in case of any staining.
• To start, pour 500ml of hot tap water down the drain. If this doesn't drain away, use a plunger to force it through. 
• Then take your unblocker of choice and following the instructions, pour it down the drain and leave it for the amount of time the manufacturer recommends. 
• Afterwards, pour another 500ml of hot tap water down the drain.

 Does bicarbonate of soda, salt and vinegar work?

You might spot online advice claiming that bicarbonate of soda, salt and vinegar can help to unclog blocked pipes.

We put this hack to the test using equal parts bicarbonate of soda (125g), salt (125g) and vinegar (125ml) on both hairball and greasy food blockages. 

The result? It seemed to do nothing but fizz. After two attempts and a 10-minute wait, the clog was still firmly in place. It took a lot of rigorous plunging action to finally dislodge it. 

How to prevent kitchen drain blockages

Serious blockages in drains are preventable most of the time. Here are some simple steps to help prevent a dreaded blocked sink: 

• Scrape plates Make sure you remove food residue from your plates, bowls and utensils before you put them in the sink.
• Drain protector Get a drain protector to catch stray bits of food residue before they disappear down the plughole.
• Enzyme cleaning sticks Dropping an enzyme cleaning stick down the plughole once a month may prevent germs, odours and blockages. However, we can't vouch for their efficacy as we haven't tested them. 
• No coffee grounds in the sink Throw away your coffee grounds in your food waste, compost or bin.
• Collect the fat Collect fat and grease from cooking in a disposable container (juice or milk carton or another non-recyclable container) before putting it in with your general waste.

For more advice on how to look after your drains, see How to unblock a sink – and what you should never pour down your drain

How to stop hair getting stuck down the drain

Prevention is better than cure. Here's how to stop a hairball clogging your drains in the first place:

• Comb before you bathe
• Pop-up plugs - if you have a pop-up plug, unscrew it every now and then to check and remove any debris. Run water down the drain while the plug is still unscrewed.
• Drain protectors - an affordable option to have an extra layer of defence between loose hair and the plughole. You can buy these from around £6 from Amazon and Robert Dyas. 
• Hair catcher - it looks like a drain protector but it's designed especially for hair. These cost from around £5 and you can get them from Lakeland and Amazon.
• Enzyme sticks - a cleaning product you put down the plughole around once a month. It won't clear severe blockages. We haven't tested enzyme sticks so don't know how effective they are. But if you want to try them, they cost from £7 at Amazon and Robert Dyas.

What are the chemical hazard symbols and what do they mean?

Many drain unblockers contain chemicals that are hazardous to us and the environment. 

Below you can see the symbols found on some products, what they mean and the safety advice for handling them. 

Chemical hazard symbols and what they mean
	Explosive (symbol: exploding bomb)
	A substance that under defined test conditions when dry or under the effect of flame or heat may explode. Read and use instructions for the given material. Ensure containers are stored in a cool, well-ventilated place with tight-fitting lids. Store away from sources of heat and ignition.  Ensure the material and its containers are disposed of in a safe manner.
	Flammable (symbol: flame)
	Flammable if exposed to ignition sources, sparks or heat. Some substances with this symbol may give off flammable gases in contact with water.  Avoid ignition sources (sparks, flames and heat).  Keep your distance.  Wear protective clothing.
	Oxidising (symbol: flame over circle)
	May cause explosion, fire or damage to living tissue resulting in chemical burns. Reacts with other substances to produce a highly exothermic reaction. Read and use instructions for the given material.  Ensure containers are stored in a cool, well-ventilated place with tight-fitting lids.  Store away from sources of heat and ignition.  Ensure the material and its container are disposed of in a safe manner.
	Corrosive (symbol: corrosion)
	May cause burns or destruction of living tissue on contact with skin. Wear suitable protective equipment (PPE). Remove and dispose safely of any contaminated clothing. In the event of contact with skin, wash immediately with plenty of water.  In the event of contact with the eyes, rinse immediately with plenty of water for 15 minutes and seek immediate medical help.
	Acute toxicity (symbol: skull and crossbones)
	May cause a severe health risk or even death if ingested, inhaled or penetration of the skin occurs even in low volumes or quantities. Wear suitable protective equipment (PPE).  In the event of contact with skin, wash immediately with plenty of water.  In the event of contact with the eyes, rinse immediately with plenty of water for 15 minutes and seek medical advice.
	Hazardous to the environment (symbol: environment)
	Presents or may present a danger to one or more parts of the environment. These substances are usually very toxic to aquatic organisms. Ensure containers are stored in a cool, well-ventilated place with tight-fitting lids. Take measures to safeguard against accidental spillage. Ensure the material and its containers are disposed of in a safe manner.
	Health hazard/Hazardous to the ozone layer (symbol: exclamation mark)
	May cause irritation (redness or rash) or less serious toxicity. May damage the ozone layer.  Keep away from skin and eyes.  Avoid release to the environment.
	Serious health hazard (symbol: health hazard)
	May cause serious and prolonged health effects on short or long term exposure. Do not swallow the material, allow it to come into contact with skin or breath it in.
	Gas under pressure (symbol: gas cylinder)
	Contains gas under pressure. Gas released may be very cold. The gas container may explode if heated.  Do not heat containers.  Avoid contact with skin and eyes.

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