I have a tray sitting on cultured marble in my bathroom where I would put toiletrees. The stone is cream colored, but now has several orange/red spots on it from when the tray got wet. I should have known better.
I know the stone is soft, and until now I've only tried using water and a towel to remove....not working at all.
Any suggestions? Was told tootpaste and softscrub may work if I just let it set for awhile.
It looks like the solution you're planning is a sort of poultice. I would try to find out the best way to make one and apply it. I would keep the stain moist and not let it dry out and set the stain.