A dremel is one of the handiest tools I have!
I once removed a bur from the ratchet of a Rossi .357 because it would hang up while firing DA. I would also use a cotton bob and polishing compound to slick up the sides of the trigger group on some "less expensive" revolvers to get rid of the "sand in the teeth" feel...
...besides, what ELSE am I supposed to use to grind off serial numbers of guns I get from my more scrupulous customers???