obviously, if silver or proof I would not touch it and coin collectors will say no, I'm sure
but, there was this one time, at band camp...... I had this token, and ONE side was trashed,really trashed, but the other side i thought salvageable, and had a Riverboat on it(imagine that) so I cleaned it and polished it and it cam out looking like new on the image side i wanted. I would never try to sell it and it is quite common, but someone gave it to me and I gave it a whirl.
Wish I had a scan of it to show before and after.