I may try to do some experimenting tomorrow. I have cashboxes full of parts from parted out games through the years - one full of metal posts, one full of screws,  one full of nuts, etc. So I've got plenty to play with and do some experimenting.

I keep thinking I'll have time at night, then something more important (bah!) pops up that the wife or kids need, etc.

How do you dry before tumbling? Just towel dry? Blow the parts out? Or just drain them and toss them in the tumbler?

I drop them on a towel, and then put them out in the sun for 5 minutes ! If I need to dry at night - I use the compressor ! Then straight into the tumbler.