Ya. I bought a rock tumbler also. Works great? Things that I find that are not of much value, I will put in a couple drops of dish soap, a tablespoon of white sand, and let her rip.
Once I found a ring from the Army at a campgrounds, just searching around my 5th wheel with my MT. Looked like class ring from the 60's and 70's for guys except it said "Army" on it. Had a red jewel, (glass) and the ring was badly tarnished, dirty, scratched. Just for the heck of it, I put it in my tumbler for 2 hours just to see how much it cleaned up and how much damaged was done to it from the sand. To my surprise. It looked brand new! Looking at it under a magnifying glass, I could see the scratches from the sand, but it wasn't bad at all. Not that I would do it to old coins, or good jewelry, but it comes in handy for stuff you want to clean up that are not worth allot.
I even thought of wearing it since I was at Bragg in the mid 70's, but the sucker weighted a ton.
What I like about the tumbler is the cup is rubber, so it doesn't scratch your finds worse. For all i know. They may have always been rubber. I never had one when I was a kid.