Alright, so someone on here not long ago made mention of using a rock tumbler for cleaning up small parts, nuts, bolts, etc. So I thought, sounds like a pretty labor free way of saving old hardware. However, what I would like to know is, what do I tumble them in? Do I get some clean sand to throw in there for some polishing too? At the moment I am thinking evaporust (or maybe vinegar, way cheaper) and sand, but I was hoping someone could offer some advice on this practice.