The cloth trick . This method, which is the simplest and quickest, involves wiping the stain with a cloth soaked in vinegar. This ingredient is a natural deoxidizer that removes the yellow or black stain while polishing and disinfecting thoroughly. If the stain doesn't come out, apply vinegar directly to it and wipe it with the cloth after about 30 minutes.
Lemon . This citrus fruit also has disinfectant and bleaching properties, which help remove stains. Rub half a lemon directly on the dark stain, let it sit for a few minutes, then wipe with a cloth. Repeat if the stain persists.
Borax . This is one of the most powerful ingredients for removing stains from almost any bathroom surface. Apply borax directly to the stain, then pour vinegar over it. After 20 minutes, scrub with a sponge, then rinse with water and dry thoroughly. Wear gloves and a mask while applying borax.
