Reading this gives me nightmares of the loose skin of the sack easily getting caught and shredded in the clippers.
And I guess it can be done, but I have trouble imagining any sort of guard giving you a close enough trim.
And, two days later, my balls still hurt a little from any direct pressure placed on the injury.
EDIT: Black Lushus, no, I knew what you were talking about. I just couldn't imagine it working or being pain-free. But then there was a time when taking any sharp objects near one's junk seemed like a fool's game.