How to Remove Toilet Bowl Stains | HowStuffWorks
Borax Powder - Borax powder is a very powerful cleaning agent that's not found in a supermarket, but in a hardware store. Shut the water supply to the toilet tank and empty the bowl by flushing it once. Sprinkle the powder directly on the stains and rub them with a toilet brush. After scrubbing, let the powder sit for thirty minutes.