Daniel, I have one of those Harbor freight jobs that I bought at a cheap price. I also have two kinds of the media. Plastic diamond shape things and Walnut shells.
None of it works to my satisfaction.
I did research on building a tumbler and there is much info on the web about it.
There are high quality tumbler versions available but I couldn't justify the cost.
Most of the time for my pieces it takes a
combination of processes to restore the small items and keep track of them.
We have a High quality Aircraft repair business in town that I use when I have bulk items. They carefully soak, strip and either Cadmium plate, anodize or other processes to your request. I found that to be the best deal.
However certain parts (rare or unusual) need to be taken watch of in case you want to keep them period correct or stock. Some unique little bits are just to hard to come by.
A L A N F R A K E S ~ Tulsa, OK