You might try dipping in or spraying with acetone.
They have pencil sized sandblasters but you’ll need an air
compressor or bottled (safe) gas. CO2 or nitrogen. These blasters are
pretty cheap sometimes, like $50 or so. My impression is however they
will be too coarse.
Or if you’d like a nice random satin pattern. toothbrush with pumice
or some other fine grit.
You could also just buff them on a polishing lathe if its just the
scratches that bother you.