Maybe a liquid latex or liquid rubber.....dip the metal part in and let it dry, I'd think it would make those edges softer!
I have a beautiful hair barrette clip, but the snap shut metal hardware feels a little sharp to the touch. What can I wrap onto it to make it usable?
Take a nail file or emery board to it and soften the edges or point.
clear nail polish should help soften the touch and help it hold its look as well.