For example, applying white vinegar or lemon juice and scrubbing with a toilet brush typically works on newer stains. You can also try mixing white vinegar and baking soda if you need a stronger scrub. For older stains, using an industrial-strength cleaner like CLR should do the trick.
Citric acid
More importantly, it's probably even more effective than vinegar for getting rid of that brown stain in the toilet. Simply pour a kettle of almost boiling water into the bowl, follow up with 250ml of citric acid, and leave it for some hours – preferably overnight. The next day, scrub and flush.
If you get brown stains in your toilet bowl, the good news is that it's not caused by anything that you, ahem, do in the bathroom. It's actually due to high concentrations of minerals in hard water, like calcium, iron, and manganese, that build up inside the toilet bowl over time, according to Hunker.
Distilled white vinegar is a natural cleaner, disinfectant, and fungicide, and baking soda is a natural deodorizer, whitener, and mild abrasive. This stain remover combo works best when you need to know how to get rid of toilet stains caused by minerals or mold.
Pour 1/2 a cup of hydrogen peroxide onto stains. Then sprinkle 1 cup of baking soda on top. Let the mixture sit for 15 minutes. Scrub with a toilet brush and flush.
A much better solution is to use some WD-40 Multi-Use Product. Most people don't know that WD-40 can solve many of their household cleaning needs quickly and easily. When cleaning a toilet bowl, WD-40 works by softening the rust and lime deposits, so they can be easily wiped away. You don't need to use much of it.
As a one-stop cleaning solution, pour one cup of bleach around the bowl. Then tackle every inch with a toilet brush or a handheld scrub brush. Let it sit for five minutes, then flush.
Regular cleaning keeps the bowl white and prevents hard-to-remove stains from building up inside the bowl. However, for more deep cleaning, you can use bleach, white vinegar, Borax or other store-bought cleaning products.
Brown stains are the result of hard water and not your cleaning wrongly. Don't use bleach as it will only bleach out the stain, but not remove it. Use a clean brush with plastic bristles.
The carbonic acid that is in coke is what helps to clean toilet stains. Picture the acidity slowly working its way through the stains, melting them away. It can take a while depending on how stubborn the stain is which is why it's vital to have a suitable cleaning method depending on how bad the toilet condition is.
"The biggest don't when it comes to toilet tanks is bleach—do not use bleach or products containing bleach inside the tank, as it can corrode the internal parts of your toilet. If you are aiming to remove tough stains from the tank, I also recommend white vinegar diluted with water."
Leaving bleach in a toilet overnight is fine, but you shouldn't leave it any longer, or else it might corrode your toilet. If you do decide to leave it in the bowl overnight, let other members of your household know so that they don't use the toilet and accidentally mix the bleach with ammonia from urine.
Make a paste by mixing 1/2 cup of Borax and enough vinegar to form a thick paste. Spread the paste immediately onto the hard water stains in the toilet so they are completely covered by the paste. The Borax will harden quickly so don't add the vinegar until you are ready to apply the paste.
Add 1-2 cups of white vinegar to the bowl and leave it in the toilet for 20-30 minutes. After this, gently scrub the walls of the toilet with the brush or sponge and rinse the white vinegar and baking soda away with water. This cleaning method should take care of your stains.
Hydrogen Peroxide and Vinegar
“Combining these two creates peracetic acid or corrosive acid, an irritant that, in high concentrations, can harm the skin, eyes, throat, nose, and lungs,” says Bock.
The muriatic acid will absolutely remove the hard water deposits that are trapping the stains. The longer it soaks, the less you have to scrub. Never use a metal scraper, screwdriver or other tool to dislodge any deposits. The acid will do the work for you; it just may take awhile.
Grab some gloves and use a Magic Eraser to go to town on toilet bowl stains. Some users even recommend cutting a piece off and letting it dissolve the bowl to remove that unsightly ring all on its own.
To remove tough stains, add the baking soda and vinegar mix to your toilet and then allow the solution to sit in the bowl for up to 30 minutes. During that time, the chemical reaction between the sodium bicarbonate and vinegar will work to eat away at those stubborn hard water stains.