In theory, some kind of metal filler could work…
Most times for dings and scratches what I see recommended is rubbing or sanding it down to smooth it out with a metal spoon, denim, things like that.
It is easier to smooth around the scratch or ding than it is to glue extra material on to cover it up. I guess with cars this is somewhat easier since you fill a dent with filler material, then that always gets covered with primer and paint. Metal anodization on yoyos is a whole different ballgame!