I honestly don't know the exact reason, just something she has always done. She uses the stuff for everything. I can't even imagine the dry scalely mess my skin would be if I did that every night.
I also ment to tell y'all that Signature Minerals has a free sample kit if you want to try it. I think you just have to pay like $4 in shipping. It's under their kits page. I think everyday minerals has a free kit too, but I've never used so I don'y know how thet are.