WD-40 to Clean a Toilet? – What to Do and Not Do

Last Updated on June 13, 2022 by toilethaven

Can You Use WD-40 to Clean Your Toilet?

WD-40 is not used as an everyday toilet cleaner, rather it is used to remove stubborn hard water stains from a toilet bowl. It is should be used as a last result after other ways of removing the stains have not borne fruits.

Most people see WD-40 as something that should be stored somewhere in a garage but not in the bathroom or kitchen. They are right though. WD-40 is an excellent penetrating oil that is used to loosen tight connections and also remove/prevent rusts from parts.

WD-40 will remove the stubborn hard water stains/rings from a toilet bowl. Just spray a little bit of it around the affected area and wait for 15 minutes. Scrub the bowl with a toilet brush to remove the stains. Wipe the WD-40 with a rag instead of flushing it down the toilet.

WD-40 is not eco-friendly and should not be used as a regular toilet bowl cleaner especially if on a septic system, as it will kill the good bacteria in the septic tank. When used to remove hard water toilet stains, wipe it off from the bowl with a rag instead of flushing.

I have written an article reviewing some of the best toilet bowl cleaners for people on a septic system. Read it here.

If you live in area with hard water, you might have without a doubt noticed brown, black, yellow or whitish/cloudy stains on your toilet bowl. If you removed the toilet tank lid you would also see these stains.

What Causes Toilet Stains?

The brown toilet stains are caused by a high concentration of iron and/or manganese in the water. The iron which is more notorious reacts with oxygen to form iron oxide which is commonly referred to as rust.

Black or green stains are as result of bacteria present in the water while whitish/foggy/cloudy stains are as result of calcium deposits. These stains can make a toilet look way older than it actually is.

Hard water toilet stains appear anywhere inside the toilet bowl but are more likely to form a ring at the bottom of the bowl around the waterline. This is because the hard water is stagnant there and with a constant supply of oxygen.

Although some toilet cleaners are advertised as being capable of removing the toilet stains in one go, the truth of the matter is that it is impossible to do that as long as hard water still flows into your toilet.

How to Remove Hard Water Stains in a Toilet Using WD-40

Most hard water stains in a toilet bowl are brown in color. This are caused by high presence of iron and/or manganese in the water. White/cloudy stains are caused by calcium and is an indication of a high lime concentration in the water.

Whether you toilet’s hard water stains are caused by iron, manganese or calcium, WD-40 will help you get rid of them.

  • Remove the water at the bottom of the toilet bowl using a cup or a sponge.
  • Spray the WD-40 on the toilet bowl targeting the stains.
  • Give the WD-40 2 to 5 minutes to dissolve the stains.
  • Use the toilet brush to scrub the toilet bowl including the rim and the outlet.
  • Flush the toilet to confirm that all stains are removed.

It is advised that you only use small amount of WD-40 instead of pouring a large amount as you would do with vinegar. While shopping for the product be sure to buy and use the low-odor type which will leave your bathroom smelling fresh.

Can WD-40 Unclog a Toilet

WD-40 will break down the clog into smaller pieces which can then flow down the drain easily hence unclogging the toilet. It is however not eco-friendly and should be avoided especially for people on a septic system.

WD-40 will kill the good bacteria inside the septic tank meaning your waste will not be broken down faster as it should.

If you have a clogged toilet and don’t have a toilet plunger or snake, there are other safer methods you can use to unclog it. Read more about them in this post.

Other Ways to Remove Toilet Stains

Although WD-40 removes hard water stains from a toilet bowl, there are other ways which you should consider too. The most common toilet stain remover is a combination of vinegar and baking soda.

Pour a cup of vinegar inside the toilet bowl and wait for about one minute. Slowly add a cup of baking soda followed by another cup of vinegar. Swish the solution around the toilet bowl after every 5 minutes for 30 minutes.

After 30 minutes use the toilet brush to scrub the bowl targeting all stains until they are all removed. Flush the toilet and wash it with vinegar about once a week to prevent the stains from building up.

In case you need to remove a toilet ring, a pumice stone will come in handy. Drop it in the toilet bowl water for 15 minutes and let it soften. Pick one point of the toilet ring and rub all around being careful not to scratch the porcelain.

Other Ways to Use WD-40

Apart from removing hard water stains from a toilet, WD-40 has tens of other uses in and outside of the house. Let us look at some of them.

  1. To Loosen Toilet Tank/Seat Bolts

Toilet tanks and toilet seats are mounting on the toilet bowl using bolts which some time are too tight and/or rusted and won’t just come off. Spray WD-40 and wait for about 15 minutes. WD-40 which is a penetrating oil will make it easy for you to loosen the bolts.

2. Cleaning Tiles

WD-40 is an excellent products for removing stains from your bathroom tiles. Just spray it on the floor and walls focusing more on the edges as well as on the base of the toilet, bathtub and other fixtures. Give it five minutes then wash thoroughly with a detergent

3. Removing gum from surfaces.

If you have young kids around the house then you know they always don’t dispose gum appropriately. This gum ends up drying against, the wall, bed, floor or any other part of the house. Spraying WD-40 on the dried gum will soften it and make it easy to remove.

4. Preserving tools

WD-40 is a great product that helps preserve tools by preventing rusting. In order for rusting to occur, there needs to be water, iron and oxygen. In fact the initials in WD-40 stands for Water Displacement. Before storing your tools away, spraying them with WD-40 displaces any water present and therefore protects them from rusting.


  1. Is it safe to use WD-40 in toilet cleaning?

WD-40 can be a great way of removing hard water stains from a toilet bowl. It is however not recommended as the go-to toilet cleaner. You should only use it to remove stubborn toilet stains and only spray a small amount on the toilet bowl

2. Does WD-40 kill wasps?

Yes. A wasp is an insect which stings its prey and also humans. It likes to build nests in hidden edges or drill holes in wooden poles. Although there are other products which can kill them, WD-40 will definitely kill the wasps in your home or keep them at bay.

3. What do hotels use to clean glass shower doors?

Hotels glass shower doors are always looking spotless. To achieve this, mix vinegar and water in a ratio of 1:3 and put the solution in a clean spray bottle. Spray the solution on the inside and outside of the glass door and wait for about five minutes. Use a non-abrasive cloth and dish soap to scrub the door then dry it completely.

4. Can I use WD-40 to clean my toilet tank if I have a septic system?

NO. WD-40 is not designed to be used as a conventional toilet cleaner. There are better products like vinegar, baking soda, coke, pumice stone etc. You only use it to remove hard water stains from a toilet bowl.

WD-40 is made of petroleum oil which does not degrade and therefore might find its way into someone’s drinking water or the ocean/lake. It also kills important bacteria found in the septic tank.

Although one use of WD-40 might not be very harmful, continuous usage should be avoided.