How To Clean A Toilet With WD40 (Hard Water Stains)

If you have nasty hard water stains in your toilet bowl that won’t come off no matter how hard you scrub, you might need to use a stronger cleaner than usual. It may surprise you to learn that WD-40 works great in situations where other cleaners just won’t cut it.

cleaning a toilet with WD-40

In this article, we’ll discuss the safety of using WD-40 in toilets and tell you what types of stains you can remove with it. We’ll also give you some tips to help keep those stains from returning.

Can You Use WD-40 To Clean Toilets? Is It Safe?

You can safely use WD-40 to clean your toilets when you’re facing a bad stain from rust or hard water. It’s not great for the environment, so you certainly shouldn’t use it to replace your everyday cleaner, but if used correctly when you really need it, it is perfectly safe.

How To Clean A Toilet Using WD-40

Follow these simple steps when you need to use WD-40 to remove a nasty stain from your toilet (for mold stains, use this guide instead):

WD 40 for hard water toilet stains

1. Purchase Some WD-40

If you’ve never used WD-40 before, you probably won’t know where to find it. After all, it’s not in the same aisle as the rest of the cleaning supplies. You can find it at any home improvement or hardware store.

You might even be able to find it in a superstore in the automotive department or buy it online. Since you plan to use it to clean the toilet, you should look for a bottle with a wide sprayer so it will cover more surface area.

2. Prepare Your Bathroom

Now that you have your WD-40, take a few precautions to prepare your bathroom. If there’s a window, you should open it and turn on the fan to improve ventilation.

Next, turn off the water supply to your toilet and flush to remove as much water from the bowl as possible.

3. Spray WD-40 On The Stains

WD-40 is powerful, so you won’t need to use much of it. If you’re only dealing with a ring from hard water, just make a 10-second sweep directly on the ring.

If you have more extensive stains, spray it around the entire bowl for no more than 20-30 seconds. Let it sit for 15 minutes or so to soak into the stain.

For extremely stubborn stains, you may want to let the WD-40 soak in overnight.

4. Scrub Your Toilet

When you’re relatively sure it’s done its job, use a toilet brush to scrub it off. When you’re finished scrubbing, flush the toilet to get the dirt out of the bowl.

If it doesn’t remove the entire stain on the first application, you can try again and leave the WD-40 on the stain longer this time.

Does WD-40 Remove Hard Water Stains In Toilets?

Yes, WD-40 removes hard water stains from toilets. It cleans hard water stains so well because they are caused by mineral deposits in the water oxidizing on the surface of your toilet bowl. In fact, some hard water contains iron, which causes rust. WD-40 is explicitly formulated to remove rust, thereby removing the hard water stains.

Does WD-40 Remove Rust Stains From Toilets?

Yes, WD-40 removes rust stains from toilets. This cleaner is specially formulated to break down rust wherever it forms, so getting the stains off your toilet bowl will be a breeze.

Tips To Prevent Hard Water Stains In Your Toilet

When you finally remove all the hard water stains from your toilet, follow these simple steps to keep them from returning.

baking soda

Pour Vinegar Into Your Toilet

If you have a problem with hard water stains, use vinegar in your toilet to break down the mineral deposits that try to build up in your toilet.

To harness the cleaning power of vinegar, just pour a cup into your toilet, spreading it all around the bowl. Let it sit for 15 minutes or so, then scrub it off with a toilet brush.

Repeat this process once a week to keep hard water stains away.

Add Baking Soda

If vinegar alone isn’t enough to keep the stains out of your toilet, try adding some baking soda as well. First, pour a cup of baking soda into your toilet.

Make sure you hit every area of the bowl. Next, sprinkle ½ cup of baking soda around the toilet bowl. Allow it to stand until the fizzing stops, then scrub it with a toilet brush.

For best results, repeat this process weekly.

Try Epsom Salt

If vinegar and baking soda don’t work or you would prefer a different method, try using Epsom salt. This salt has a fizzing reaction when combined with water, much like baking soda and vinegar.

To clean your toilet, pour a cup of Epsom salt into the bowl, leave it for 20 minutes, then scrub with a toilet brush. Use this method every week to prevent hard water stains from coming back.

How Else Can I Use WD-40 In The Bathroom?

There are other jobs that WD-40 can tackle aside from breaking down hard water stains.

For instance, if you need to remove the toilet lid but the screws have corroded, spraying them with WD-40 can help loosen them for easy removal.

Similarly, if you need to remove the entire toilet but the bolts have rusted, using a bit of WD-40 will make it much easier to get them free.

You can also use WD-40 to remove rust or hard water stains from bathtubs, showers, or tile floors. Simply spray the product onto the stained surface, leaving it for 15 minutes.

Depending on the severity of the stain, you may even want to leave it to soak overnight. When you are satisfied that it has soaked long enough, scrub the treated area with a scrub brush, then rinse and wipe clean with a microfiber cloth.

WD-40 is also great for removing stains such as hydraulic fluids on your clothes.


Can WD-40 Remove Clogs From Toilets?

Yes, WD-40 can unclog your toilet by breaking down the material causing the clog. However, it won’t work on every clog, like if your child puts a toy in the toilet.

You should also take care not to use it if you have a septic system, as it will kill the good bacteria in your septic tank and prevent the waste from breaking down all the way.

If you need to unclog a toilet, you should try using a toilet snake or baking soda and vinegar before you reach for the WD-40.

Is WD-40 Safe To Use If I Have A Septic System?

Although occasional use may be okay, using WD-40 in a toilet with a septic system is not recommended.

It is a powerful cleaner that will kill off the good bacteria in your septic tank and keep the waste from breaking down properly. It’s not a great idea to use WD-40 often, no matter what system you have, because it’s terrible for the environment.

There are many more eco-friendly cleaners you should choose for regular use.


Hard water stains in the toilet are an unsightly problem that plagues many households with well water. If you’ve tried everything to remove those stains to no avail, give WD-40 a try.

It’s specially formulated to remove rust, so if your hard water stains are caused by iron or manganese deposits, WD-40 will remove them without any trouble at all.

You can also use it on other bathroom surfaces that have been affected by hard water stains, like bathtubs, showers, and wall and floor tiles.

Even though it works wonders on toilet bowl stains, you shouldn’t use WD-40 to replace your regular toilet cleaner. It’s not good for the environment and can damage the ecosystem in your septic tank if you use it too much. 

Once you’ve removed your hard water stains with the help of WD-40, you can keep them from coming back by using vinegar and baking soda or Epsom salts to clean your toilet every week.

Shauna Stone