A month or so ago, Mrs. G. bought us one of these microplane
cheese graters. It's pretty cool technology, actually. They're
chemically dissolved rather than stamped. It goes through
parmesan like butter. Unfortunately, it also goes through
knuckles like butter. Just FYI.

Following your link, I was intrigued by the product line. It looks like good stuff, but I couldn't figure out how my my deeply cracked feet got involved.
Odd, no?
The secret, Ted, lies in this sentence from the page:
"Rub a small amount into soles after Foot File use."
Ouch!
Well given that the original field of application was as surgical instruments for filing bones I don't see why they wouldn't be pretty effective.
I have one for filing wood.