First, as I read my previous post, I would say again that a coin tumbler and a rock tumbler are the same. Only difference is the contents and how long you run the machine. Put some nice rocks or some rough gemstones in, along with sand ond other grit etc., in and run it for a few days or, at least, several hours and you notice smoothing of edges of rocks and they come out shiny and polished. Put in some coins and some detergents and more mild abrasives along with some coins and run for 20 minutes or so and you clean coins.
Has a lot to do with how long you run the machine, and if you just want to clean your items or if you want to polish and more agressively shape and alter their surfaces.
That said, if you look at how a rock tumbler works... It either rolls a canister back and forth at a slow speed, or rolls the container around and around slowly, tumbling the aggregates and coins, etc., across and over each other taking off grit and grime and cleaning the coins. Or, if done for a longer period of time, the aggregate will begin to remove parts of the surface, round over and smooth edges etc.
Being that it works so slowly, you could, concievably, take any small jar or a Tupperware or Rubbermaid type container that closes tite, fill it with some cleaning medium dry like rice or beans, corn or nut shells... Or, add some water and detergent and another suitable suitable cleaning medium and just roll it all back and forth across a table, swirl it around or shake it and so on. Do this for about 20 minutes or so and you would probably do as well as if you had used a tumbler. You DO NOT need to shake vigerously or anything. Jus keep everything moving.
The main issues is if it closes titely, and won't spill all over, and what you put in there with your coins and that you need to keep the cointents moving for upward of a half hour without any interruption.
![:-\](https://www.treasurenet.com/smilies/undecided.gif "Undecided :-\")
