I was freaking out because the permanent ink at the bottom of my bottle of face wash seeped into the plastic of my shower unit. But! This site had wonderful recommendations. I can state that a denture tablet sprayed with hot water and left overnight will get pesky stains out.
Shampoo is great for getting makeup stains out of clothing.
And when you cut yourself shaving and don't notice until it's on your socks, hydrogen peroxide is great. I actually ran across a site which said shampoo works well too, but I haven't personally tried that.