Ron Wanttaja wrote:

Going to try the rock-polisher next. My wife has a small one, with
buckshot-sized media for cleaning metal for jewelry work. Think the media is
too large, so I might try (unused) kitty litter.

Ron Wanttaja

Try ground corn cob from the pet store (sold as small animal bedding) in
the rock tumbler. Add 1 ounce of automatic transmission fluid and
tumble for a couple hours before adding the parts to get it mixed.

Tony