Don - (chuckle) I've got a teeny 1 1/2" bowie knife that my brother made on the grinder when he was a kid. He made miniature rifles and swords, too. But he didn't tenderize his fingers!
I used the key machine alot when I worked in a hardware store - imagine your fingers slipping off into THAT. (I never had that happen, luckily.)
For "digital" traction, keep hands soft with a little lotion, or try the office supply store and get a little container of that waxy stuff that people dab on their fingers so they can sort through piles of papers.