You actually can, but I admit I never have hp'ed them, but knew of a gal in another forum that only made hp and she made beautiful salt bars. I do know she used lactic acid and some extra water when making her salt bars. The forum is now down and I have never seen her in any other forums. She was the best I have ever seen at hp'ing.I'm lovin' this thread right here. I kinda wish I could HP a salt bar, but I definitely have to make a pumpkin soap.