Microdermabrasion? Wonderful what new tems the marketing people come up with! I call it sanding.
The principle of using a finely graded rough surface is tried and tested. Lumps of pumice stone have been removing rough old dried skin from feet (probably) since Pompeii was buried in the stuff.
Ever since the days when I used to dry stone wall in streams, I have found wet-and-dry paper (about 400 grade grit) useful for taking rough skin down to smooth, followed by a decent hand cream.
The technical thing is that the dry rough skin is dead and can be removed by sandpaper. Once you start to get to the "live" skin, it alters in texture and does not sand off in the way old dry stuff does. When you reach that point, you can stop. It also works for removing hairs - the ones on your toes (especially useful for the well groomed hobbit).