Hairspray Stains on Tile
I was called in to inspect a floor that had mysterious white spots on the darkened tile. Plumbers had worked under the homeowner's vanity and she thought that the plumbers had done something to her floor.
I grabbed some scouring powder and a damp rag and made a circle in the center of the tile with the powder and some elbow grease. The dark finish came right off, revealing the bright original finish of the tile.
Moral of the story: make sure you put a large mat or beach towel down before using hairspray over a tile floor!