Finally Coke has a useful application! The same ingredients in coke that damage the enamel and rot your teeth is also pretty darn good at clearing limescale and other, ummm, stains on your toilet. So put a can of coke to good use for once and pour it around and into your throne, the carbonic, citric and phosphoric acids in it will break down the stains if you leave it in there overnight. Note, although the stains will go, you’ll still need some bleach for the bacteria and germs your toilet harbours.
Give it a try!