I have been experimenting lately with different ways to clean/polish cases as I dont have a tumbler. I found this automotive product called Never-dull, its in a tin can and inside is a chemical impregranted wadding material. You just pinch off a bit of the wadding, and rub it on the metal. The packaging recommends using it on brass. I can't find anything about ammonia on it, which is good. The chemical has just a general oily/slovent type smell. To get a mirror/like new finish, chuck the case in a drill in a lee trimmer, polish first with some fine steel wool, then hit it with the never dull. Finish by spinning the case in a clean rag to remove residue.
Anyway, anyone else every try this? I've been getting good results, just a little concerned that the chemical might be bad for the brass (like ammonia is). Your thoughts welcome.