How to clean an old shower floor?
We have a shower floor that's 30 years old, made of -- I think -- fiberglass. It's got a textured bottom with a kind of starburst design in it, and some of the grooves have darkened. What's even more unattractive is that the floor itself is no longer really white, and none of the usual cleaning supplies have been effective. The home had been a rental before we bought it, so I'll bet no one really cared enough to do regular good cleanings. Short of replacing the shower (which we really can't afford to do), I'm at a loss. Can anyone suggest something? Thank you!