There is a YouTube video from a few years ago. Shows Phil Mickelson @ the LA Open and he's using a wedge on the GREEN....there was a sand trap in the middle of the green and he needed to hit his ball over that trap to reach the hole. His club never even touched the surface of the green and he left his ball about 4 inches from the hole.
So, surely, using a "wedge" on the green is legal.
I just watched that video a few minutes ago.....so, it's still there to watch.