10 of the dirtiest parts of your home – and how to clean them

Most of us clean our homes pretty regularly, but some of the dirtiest places are the easiest to overlook. From remote controls to washing machine seals, these hidden hotspots that can harbour mould, bacteria, dust and grime if left unchecked.

With the help of Dr Primrose Freestone, associate professor in clinical microbiology at the University of Leicester, we've uncovered some of the dirtiest parts of the average home – and how to clean them.

1) Back of the toilet

While most people regularly clean the toilet bowl, the area behind and around the toilet is often overlooked. These hard-to-reach spots can harbour dust, moisture, mould and bacteria, particularly in poorly ventilated bathrooms.

How often should I clean it?

Dr Freestone suggests cleaning behind the toilet when you clean the toilet bowl about once a week.

She says that the back of the toilet can be a hotspot for 'black, slimy mould', as well as skin cells and airborne bacteria that can settle on surfaces over time.

She adds: 'A bleach-based spray can be very effective against mould and fungal spores.'

Popular bleach cleaning sprays

• Flash Bleach Cleaning Spray with Eucalyptus Scent, 800ml SQUIRREL_TEXT_50029351
• Astonish Multi-Purpose Cleaner with Bleach Spray, 750ml SQUIRREL_TEXT_50029445
• Domestos Multi-Purpose Bleach Cleaning Spray, 700ml SQUIRREL_TEXT_50010923 

• If you're using bleach-based products, keep children and pets away from the area until it's been cleaned and aired. We've got more tips on things to watch out for when using bleach.
• Always wear gloves and old clothes, follow the manufacturer's instructions and never mix bleach with other cleaning products, particularly vinegar, limescale removers or other acidic cleaners, as this can produce harmful gases.
• If you don't want to use bleach, consider one of our best bathroom sprays.

For more expert tips, see our guide on how to clean your toilet

2) Kitchen sink and drain

As a busy food preparation area, your kitchen can harbour food debris that bacteria feed on, especially the sink and drain.

How often should I clean it?

Dr Freestone says: 'It should be cleaned every single day and disinfected. There will be food debris washed down the plughole which bacteria will feed on, which increases the risk of contaminating food.'

For our recommended products, see our kitchen cleaner reviews.

If a blocked sink is causing you kitchen chaos, see our advice on how to unblock a sink and the drain unblockers we recommend

3) Tech: keyboards, remote controls and mobile phones

Keyboards, remote controls and mobile phones are some of the most frequently touched items in the home. Every tap and swipe can transfer oils, sweat, skin cells and bacteria from our hands, allowing grime to build up over time.

Add in crumbs from eating at your desk or on the sofa, plus the dust and debris that can collect between keys and in crevices, and our everyday tech can get surprisingly grubby.

How often should I clean them?

Dr Freestone recommends cleaning these devices most days: 'Wherever people touch, it deposits skin cells and bacteria. I've seen microscopic fungi growing on keyboards.'

Cleaning your laptop

Before you start cleaning, make sure your laptop is switched off and unplugged from the mains. Then open the lid, turn the laptop upside down and gently tap to dislodge crumbs and other loose debris from the keyboard. You can also use a soft brush to clear between the keys.

To clean the key surfaces and touchpad, manufacturers recommend lightly dampening a lint-free cloth with isopropyl alcohol (70% or higher) and wiping gently. Make sure the surfaces don't get too wet and, importantly, that everything is fully dry before restarting the laptop. 

Cleaning your phone

When cleaning your phone, start by turning it off and unplugging any cables, then leave it to dry before turning it back on. It's important to avoid getting moisture into any openings, such as charging ports, speaker grilles and, if your phone still has one, headphone ports.

Manufacturers say you can use 70% isopropyl alcohol wipes to disinfect your phone. Apple also says 75% ethyl alcohol wipes are safe to use on its devices. After disinfecting, wipe with a soft, slightly damp lint-free cloth. 

Never use metal tools inside your charging port, as they can short out the internal pins. A wooden toothpick or a dedicated plastic soft-pick is a much safer alternative for dislodging debris.

Similar disinfectant wipes can also be used to clean remote controls. 

Popular antibacterial wipes

• Antibacterial Wipes with 75% Isopropyl Alcohol SQUIRREL_TEXT_50029717
• Zeiss Anti-Bacterial Smartphone Screen Wipes SQUIRREL_TEXT_50029722 

If you feel like giving your earphones a once-over while you're at it, be sure to read three mistakes you're making when cleaning your AirPods (and other headphones)

4) In and around the fridge

Keeping your fridge clean is about more than tackling spills, stains and lingering smells; it can also help prevent bacteria from building up.

In a Which? investigation, 19 of 50 swabs taken from 10 fridges showed worrying levels of germs, including bacteria associated with respiratory, urinary and food-borne illnesses.

Dust and debris can also build up behind the appliance and on the condenser coils, reducing your appliance's efficiency.

How often should I clean it?

Dr Freestone recommends checking use-by dates and cleaning inside your fridge at least once a week: 'Get rid of old bits of cheese, or any other out-of-date products, because mould can penetrate other food and spread mycotoxins which can cause serious illness.'

When deep-cleaning your fridge, pull it away from the wall, unplug it and gently vacuum the condenser coils using a brush attachment if you have one. Then, use a separate brush to remove any remaining dirt and dust from the coils, and vacuum again to pick up any mess.

Does your fridge whiff a bit? Find five reasons your fridge smells and what to do about it

5) Washing machine seal

Thanks to warm, damp conditions, the rubber seal around the washing machine door provides the perfect environment for mould, bacteria and fungi to thrive.

Dirt, detergent residue and debris can also become trapped in the folds of the seal, leading to a smelly washing machine, among other issues.

How often should I clean it?

If you use your washing machine regularly, Dr Freestone recommends wiping it after each wash and sanitising its interior once a month: ‘It’s amazing what’s growing in your washing machine. Mould and bacteria can congregate in the rubber seal, so try to give it a clean after each wash.’

Wipe the seal with a microfibre cloth dipped in warm water with washing-up liquid.

If you notice mould building up, use an old toothbrush to scrub off any stubborn patches. Make sure not to be too firm, as this could lift the seal away from the metal. You can also run regular maintenance washes – typically every 30 washes – to keep the drum clean.

If mould has had too long to fester, it may have sunk into the porous rubber of the seal and be impossible to remove. If this happens, you may need to replace the door seal.

How to get rid of mould How to get rid of it, plus five ways to prevent it in the first place

6) Mattresses

We spend around a third of our lives in bed, so it's no surprise that mattresses can harbour sweat, dead skin cells, dust mites and bacteria. According to The Sleep Council, the average adult sheds around 454g of dead skin each year, much of it ending up in their bed, while the average mattress contains around 10,000 dust mites that produce more than two million droppings.

When we surveyed Which? members, 65% had never cleaned stains from their mattress, 30% had never vacuumed it, and 17% had never aired it.

How often should I clean it?

It all depends on the mattress and the person sleeping on it, but every six months is advisable, as is regularly flipping and rotating your mattress.

Dr Freestone recommends vacuuming your mattress with the upholstery attachment to remove dust and skin cells, or treating it with a steam cleaner to reduce house dust mite levels. 

Finally, air your mattress for a few hours to let the fabric breathe, as drying helps inhibit fungal and bacterial growth. Dr Freestone also advises washing your bed sheets once a week or every two to three days in hot weather or if pets come on to the bed.

You can use a mattress protector to protect it from dust and sweat.

For an in-depth guide to the big clean, find out how to clean a mattress

7) Ovens

Every time you cook, grease and food residue build up inside your oven. Left unchecked, this can turn into stubborn burnt-on grime that's harder to remove and may even affect cooking performance.

How often should I clean it?

How often you clean your oven depends on how much you use it, but Dr Primrose Freestone recommends giving it a thorough clean around once a month: ‘When you cook, it leaves a coating of oil that gradually carbonises, producing fumes each time you use the oven.'

Before cleaning, switch the oven off at the mains and allow it to cool completely. Brush away any loose food debris, then apply an oven cleaner according to the manufacturer's instructions. Avoid spraying directly on to the fan or, for gas ovens, the gas supply elements and pilot light. 

You can also steam your oven with lemon water to help loosen dirt before using an oven cleaner.

I was a professional cleaner for five years. Here are the cleaning tips I swear by: read the top hacks from the trade

8) Door handles

Door handles and other frequently touched surfaces can quickly accumulate germs as they're constantly being handled throughout the day, yet they're often overlooked when cleaning. 

How often should I clean them?

Dr Freestone recommends cleaning these high-touch surfaces about once every one to two weeks. 'Hands carry germs into the house. But there are some parts of the house that are often overlooked, so it's important to give them a regular clean.'

Wipe door handles with a suitable antibacterial or disinfectant cleaner, following the manufacturer's instructions. Check that the product is suitable for the surface you're cleaning, as some disinfectant wipes and sprays aren't recommended for painted or varnished wood, fabrics, mirrors or other delicate finishes. 

9) Down the sides of sofas and chairs

Crumbs, dust, pet hair and skin cells can all collect down the sides of sofas and upholstered chairs, making them an easy place for bacteria to build up.

How often should I clean them?

Dr Freestone recommends thoroughly cleaning upholstered furniture every three to six months. If you have pets that shed heavily, she advises vacuuming your sofa every day to keep on top of hair, dirt and pet debris: 'There are probably more bacteria down the side of your sofa than on a toilet seat, due to how rarely people clean there.'

Vacuum down the sides and between the cushions regularly, using the soft brush or crevice attachment, paying particular attention to the gaps between cushions where crumbs, dust and pet hair collect.

Before using any cleaning product on your sofa, check its care label and test it on a small, hidden area first to make sure it won't damage the fabric.

To deep clean stains, mix a little warm water with a mild detergent or fabric cleaner, then dab the stain gently with a clean cloth. You can also use a fabric upholstery cleaner, following the instructions, before cleaning it off and drying thoroughly.

If pet hair is becoming troublesome in your home, have a look through our best vacuums for pet hair

10) Carpets

Carpets trap dirt, dust, pollen, fungi and other debris when it's brought in from outside. Over time, this build-up can affect both cleanliness and indoor air quality. 

How often should I clean them?

How often you vacuum depends on how much foot traffic your home gets, but Dr Freestone recommends vacuuming carpets every day where possible. Every carpet should also be deep-cleaned periodically.

She says: 'If you wear shoes from outside on your carpet, you can bring in whatever you've stood on, which is then deposited on your carpet.'

If vacuuming daily is too much of a chore, aim for twice a week. Alternatively, consider a Best Buy robot vac, so it can do the hard work for you.

If your carpets are in dire need of some TLC, our Which? recommended carpet cleaners and carpet stain removers could help make cleaning them less of a chore.

Find out what an ex-professional cleaner still keeps in her cleaning kit