6 laundry detergent hacks not to try

There's a lot of advice online on how to save money by making your laundry detergent go further. We tried some of these hacks in our lab to see if any of them actually get clothes clean, and we asked the British Skin Foundation whether any of them could cause skin problems. 

We tested these in a Best Buy washing machine that excelled in our tests when we used detergent in the normal way. So we know for certain it's the hacks that don't work – not the machine. 

Watch our video above to see how ineffective – and even dangerous – some of these laundry hacks could be. Read on for more details, plus what you could do instead to save money when washing your clothes. 

We've tested 30 laundry powders, liquids and capsules to see which are best for busting stains. Read our laundry detergent reviews to compare effectiveness

1. Adding bicarbonate of soda to your laundry detergent

This is one of the most common pieces of advice we've seen – using less detergent and topping up with bicarbonate of soda, also known as baking soda. 

We've seen claims that it helps to remove stains, softens the water so you can use less detergent, gets rid of smells and makes whites whiter. It's also claimed to be great for allergies, and one comment on social media insisted that bicarbonate of soda helps water to grab the dirt. 

There's truth in some of this. Our tests have found it to be one of the best home remedies for treating stains, but we're talking spot-treating, not adding scoopfuls of bicarbonate of soda into your laundry load. 

Although it helped to shift stains in our testing, baking soda can irritate the skin and lead to underarm rashes, redness and burning.  

2. Using washing-up liquid instead of laundry detergent

Washing-up liquid didn't do a good job of getting clothes clean in our testing, making almost no impact on stains. 

You also risk creating a foamy mess in your kitchen when you open your washing machine, which you'll then have to mop up. 

From a health perspective, Dr Phillips explains that washing-up liquid usually contains chemical detergents, which are noxious skin irritants. 

Keep your plates and cutlery sparkling clean with our reviews of the best washing-up liquids and best dishwasher tablets

3. Using shower gel as laundry detergent

Of course you can use shower gel to handwash the odd item of clothing if you're in a pinch because you didn't bring enough socks on holiday. 

But your clothes won't be anywhere near as clean as they would be if you washed them properly, and you certainly shouldn't use shower gel as a regular substitute for laundry detergent. 

Shower gel made very little impact on dirty clothes in our test. By using body wash, you're not removing any dirt or bacteria sitting deep within the fibres of your clothes. 

If you were considering this as a way to save money, we'd suggest you use a Great Value laundry detergent instead, which works out at around 10p per wash. 

4. Mixing washing powder into a paste to use as a liquid

Some people prefer to buy powder because it's usually cheaper but find it clogs their washing machine or doesn't dissolve properly, particularly if you live in an area with hard water. 

One way to get around this is to pre-dissolve it in a little water and use it as a liquid/paste. This worked quite well in our testing, removing most of the stains we'd applied to our test fabrics. 

We also asked detergent manufacturers for their thoughts on pre-dissolving their powders. 

• Lidl told us that users should follow the instructions on the packet. 
• Aldi said you shouldn't do this with its powder because it contains ingredients that will be activated by contact with water. This should happen in the washing machine but not before, as that could reduce its performance. Aldi added that a good detergent should dissolve without leaving residue, without the need for pre-rinsing – and we agree. 
• Procter & Gamble, which makes Ariel, Bold and Fairy detergent, and Unilever, which makes Persil, told us that their powder formulations are designed to dissolve properly during the wash process, so there's no need to pre-dissolve them. 
• Unilever added that applying such a paste directly to fabrics (to treat stains, for example) could cause colour and fabric damage due to a localised concentration of bleach in powders that contain it. 

We saw some online complaints from people who said their washing machines aren't designed to take powder, so we contacted big washing machine manufacturers. Bosch and Samsung replied, confirming that all their washing machines are designed to handle washing powder, as well as liquid and gel. 

See our washing machine reviews to compare more than 200 models we've tested

5. Using too little detergent

This one depends on what you're starting with. You should definitely avoid using too much detergent, or you're just wasting your money and overwashing your clothes – which could shorten their lifespan. 

If you're going to use less than the manufacturer recommends, be sensible about it. We tested using half as much laundry detergent as recommended, and found it cleaned clothes to some degree, but not completely. 

Stains remained, for example. In the left-hand picture below, the fabric has been stained with chocolate ice cream in our tests, and on the right, the stains are still visible on the test patch even after a thorough wash. 

If you tend to tip in random amounts of detergent rather than measuring it out, you might want to try capsules. They're typically more expensive but could save you money if you regularly pour in too much detergent.

Next time your washing machine needs replacing, you could consider buying one with auto-dosing functionality that measures out the detergent for you. 

6. Not using laundry detergent at all

We've seen advice online saying it's fine to skip detergent altogether, as the power of the washing machine will agitate the clothes and get them clean. 

Sadly, this isn't true. Our testing showed this won't wash your clothes; it will just ensure they're wet as well as dirty.

Did you know that you can do more with laundry detergent than just wash clothes? Discover 5 surprising uses for laundry detergent

Should you make homemade laundry detergent?

There are plenty of recipes online for making your own laundry detergent at home. We tried a mixture of baking soda, salt, liquid castile soap, lavender oil and hot water, and it did almost nothing to clean our clothes. 

The success of your homemade laundry detergent will depend entirely on the recipe you use. Some might clean your clothes to a level you're happy with, while others might leave them dirty or faded, irritate your skin or clog your machine. 

If you want to have a go at making your own detergent, don't use vinegar, which many online articles and forum users recommend. It can damage the rubber seals and hoses in some washing machines. 

You can use vinegar to tackle a stain by mixing it with warm water and applying the mixture directly, although we recommend washing the garment afterwards to avoid it smelling of vinegar. 

Other ways to save money on laundry detergent

1. Pick the right detergent. Compare our laundry detergent reviews to see which ones will get your clothes clean and prevent you having to wash them twice. Many liquids and gels are good at keeping colours bright, while powders tend to be better for white clothes, and there's a risk of them fading colours. Capsules can struggle with ingrained stains. Some detergents cope well with most colours, but will fade yellows and blacks. 
2. Don't overwash your laundry. Find out how often you need to wash your clothes and how often you should wash your bedding.
3. Fill your washing machine to 80% capacity. Washing lots of smaller loads wastes water and energy, while overloading the washing machine could cause powder to be trapped in garments rather than dissolving. 
4. Place your capsule at the back of the drum. Manufacturers recommend doing this first, then placing your laundry on top. This stops the capsule from travelling to the front of the machine, where it could get stuck to the door seal and not dissolve properly.

You can also save money on energy and water by washing at 30°C or even 20°C, washing during off-peak hours (but don't leave your tumble dryer running when you're asleep or out of the house in case of a fire), and buying an efficient washing machine next time you need a new one (our round-up of the best washing machines can help). 

Discover other ways to save money when washing your clothes