I have a pair of dry selvage jeans that I want to accelerate the wear-in process (I know it's blasphemy to some folks, but honestly, given the fact that I have a bunch of other jeans I really like, I really don't think I can wear the same pair of jeans for 6 months straight). I've read that people suggest either using a really, really fine grit sand paper or a pumice stone and rubbing it on the denim. I have a pumice stone at home and it feels really coarse... I'd think it actually feels a lot coarser than fine sandpaper. Is it "safe" to use any pumice stone for fading, or are there less coarse pumice stones out there? Also, what's the best way to get a "natural" looking fade? I assume light pressure evenly applied on the front of the thigh areas, as well as lightly brushing against the tops of any crinkles? At what point do you stop rubbing?