I can't resist this: Can someone explain to me why Goop (the handcleaner) works? I've been doing terrible  things to my hands for years with paint and clay and dirt and grease, and I finally find this stuff that truly does just zap it away. Why doesn't it take the skin off, too?

I suppose the answer to this penetrating question resides somewhere on Ye Olde Internet, but I'm too lazy to go search it out.