Dawn: Cultured marble is the best thing for showers. It's pretty much stain resistant and non porous. If this is in a horizonal area like a wall panel, rub a little bit of lava soap and water on a scotch-brite pad, and rub the stained area gently in a circular motion until it's gone. This may leave some scratch marks, but on a horizonal piece, it won't be too much. If you want to get these minor scrathes out, you can use a buffing machine with some buffing compound as phisherman mentioned above. I have alot of other cultured marble info on my site at
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