I have heard that if you mix it in your cream or toner or whatever, it makes it sink into your skin faster and better, but I am unsure of its effect on your skin.
Ha! That's a great video of what potassium metal can do. I'm guessing that Ajthecrow might be talking about adding potassium chloride to lotions which is just another kind of salt. It doesnt add any functional benefit but at least it won't explode!