I tried it on my hand first - mainly because my mama didn't raise no fools... but it just vibrated... and I felt it, but it didn't hurt at all.
So I used it on my heels, and the end result is... those cracked dry heels I have been fighting all summer long, are now a thing of the past.
Bosch Prio, I love you !!
(pssssst... Anyone want to buy a miniature cheese-grater?)