Perhaps you have ceiling tiles hanging above you, and here and there are tell-tale splotches that suggest previous or current leaks. If you thought you’d have to replace the tiles to address the problem, you might be wrong, because you can clean them! First, fix the leak if you haven’t already done so and then we’ll get to work.
There are two ways to tackle the stain; the first one comes from a friend of mine:
Mix 1 part bleach to 1 part water and put them in a clean spray bottle. Spray the offending stain and wait 15 to 20 minutes. If the stain hasn’t faded, repeat with the spray.
This method worked okay for me, but it didn’t do much for that dark ring that invariably frames such stains. So, this is what I did:
I dipped a Q-tip in 100% bleach and GENTLY swabbed the ring of the stain. This also works if you have a particularly stubborn stain that doesn’t succumb to the spray bottle method. Just swab the entire stain with the Q-tip. This method, however, does come with a warning: if you rub the Q-tip too hard against the tile, you’ll risk actually rubbing off its white surface.
Photo courtesy of corwinok on flickr.