Toilet Cleaning Experiments

Will Lysol Disinfectant Spray disinfect the toilet?


Answer: Yes, if you spray a ton of Lysol so that the toilet is dripping wet and leave it for 10 minutes. It is best to wipe the toilet clean first because Lysol doesn't work well if there is much soil. 

Experiment details

We all expect that Lysol Disinfectant Spray will do a great job disinfecting a toilet, right? I decided to test it. Since my toilets are always perfectly clean, I used my neighbors' toilets. (I clean my toilets with this 3% hydrogen peroxide

 every day so they are always very clean.) If you would like to know who I am, please read my About the Scientist page. 

 Here is a typical toilet of a normal person who does not obsessively clean them daily like me. 

First, I swabbed the dirty toilet. I swabbed the top and underside of the seat, and around the rim of bowl. I did not swab inside the toilet bowl. I rubbed the swab all over an agar plate. 

Then I sprayed the toilet all over with a normal amount of Lysol Disinfectant Spray. I bought a brand new bottle of Lysol Disinfectant Spray (Early Morning Breeze scent) for this experiment. I sprayed all around both sides of the seat. I tried to use a normal amount. The seat was wet but not dripping.  I let the spray sit for 10 minutes. The seat was still wet. Then I swabbed the top and bottom of the seat again and rubbed the swab onto another agar plate. I incubated the plates in my warm incubator for 48 hours. 

Understanding Agar Plates

In case you are new at looking at agar plates, let me explain. Agar is a Jello-like substance that bacteria and fungus like to grow on. The whitish/yellowish dots you see are colonies (or piles) of millions of bacteria. Some types of bacteria are not able to grow on these agar plates. Viruses can not grow on these agar plates. So, just because a plate looks clean, doesn't necessarily mean that no microorganisms whatsoever were present. We assume that a clean plate means that most bacteria were killed. However, there is the possibility that the cleaning product just stopped the bacteria from growing as opposed to actually killing it. 


This toilet had visible dirty marks on it from poop and pee.

This toilet looked clean and did not have dirty spots.

The results show that most toilets (not mine but most others) have a LOT of bacteria. The results also show that a normal amount of Lysol Disinfectant Spray killed some of the bacteria but not all. So, I tried again using a TON of Lysol Spray.

I repeated this experiment on another toilet. This time I used so much Lysol Spray that it was dripping off and there was a puddle of Lysol on the floor next to the toilet. I think this is much more Lysol than anyone would normally use when attempting to disinfect something. The fumes were horrible, and I'm surprised I lived through it. 

I let the Lysol sit on the toilet for 10 minutes and then swabbed. The agar plates were incubated for 48 hours. 

As you can see, the Lysol did a great job killing bacteria in this experiment! However, since the toilet was still wet with Lysol when I swabbed it, the Lysol would be transferred to the agar plate with the bacteria. So, I don't know if the Lysol killed the germs in 10 minutes or if it took hours. So,I repeated this experiment on another neighbor's dirty toilet. I sprayed the toilet with Lysol until it was dripping. I let it sit for 10 minutes and then swabbed it. Then I wiped the toilet clean with paper towel to get all the Lysol off and swabbed it again. 

The key for Lysol, and most cleaners, is that you really need to soak the surface that you want to disinfect. It also helps if the Lysol is used on an already clean surface which is what the directions on the can say. If someone in the house is sick with a vomiting or diarrhea illness, I recommend using a stronger disinfectant like a solution of 10% chlorine bleach in water or the Clorox Hydrogen Peroxide Spray

 because stomach bugs are very hard to kill. 

Disclaimer: I can't be 100% certain that any product that I test is actually killing bacteria as opposed to somehow preventing the bacteria from growing on the agar plate by some other means.

Can I clean the toilet with 3% hydrogen peroxide?

I also cleaned a neighbor's toilet with 3% hydrogen peroxide to compare to the Lysol. I thoroughly sprayed the toilet until it was dripping with 3% hydrogen peroxide. I let it sit for 10 minutes. Then I wiped the toilet clean and dry with paper towel, and swabbed again.

As you can see, the toilet after 3% hydrogen peroxide was very clean. However, this particular toilet did not start out nearly as germy as the others. So, I can't say for sure if this point if hydrogen peroxide kills toilet germs as well as the Lysol. I'm going to repeat this on another dirty toilet when I have the chance. However, I have always been cleaning my toilets every day with 3% hydrogen peroxide for a few years. I spray the toilets off and only let it sit for about 1 minutes. (Even though, my experiments on my hydrogen peroxide page suggest that 3% hydrogen peroxide takes at least 10 minutes to kill germs.) Then I grab a handful of toilet paper and wipe it all off. The entire process only takes 2 minutes. When I swab my toilets, nothing grows. I don't know if my clean toilets are  due to the 3% hydrogen peroxide killing germs or because I wipe them down at least once each day. However, my routine seems to be working. 

Here is a comparison of what grows when I swab my toilet versus a neighbor's toilet. 

As I said,  I don't know if 3% hydrogen peroxide is better or even as good as Lysol disinfectant spray for killing germs on the toilet. However, I can't stand the fumes that Lysol produces. Lysol also leaves the toilets a little sticky. 

Can you clean a toilet with just paper towel and water?

Answer: Not good enough for my standards

Just to compare, I also cleaned a neighbor's toilet with just paper towel and water. I went over it so many times and really made heroic efforts to get it perfectly clean. I swabbed the toilet before and after.

As you can see, despite my best efforts, I couldn't get the toilet all clean with just paper towel and water. I certainly removed a lot of bacteria, though. So, if you are in a pickle and have no cleaning products, wiping of the toilet with paper towel, toilet paper, and water is a lot better than nothing. I did blot a piece of wet paper towel onto an agar plate for a control and nothing grew.