I have never made soaps in molds, but I know it works to spray a little Pam or some other product like that on candle molds. You could try that, I don't see where it would hurt the soap at all. Can't hurt to try it right?
I do, but only with the melt and pour stuff. I've never done much with the harsh chemicals required for some homemade soaps. And Kristi has it right....spray in some Pam (be skimpy...no puddles in the bottom of the mold) or other brand, or use mold release....and the soaps pop right out!