Saw a similar setup elsewhere and modified it a bit to suit my needs....
Used gas dryer - $5
5 gallon buckets - $8
2x6 wood - $8
screws - Free as I already had them
PVC items - $18
Momentary switch - $3
Gamma seal lid - $12
5 gallon capacity brass tumbler - $54 and my time on a weekend.
Used one 5 gallon bucket and assembled the pvc to make an agitator.
I found a product called Gamma seal which provides and airtight/watertight seal on the bucket
Took off the control panel, rewired the entire dryer to disable the heating element and the timers, but left the door safety and door lights active as I have a 2 year old who might open it....Added a new switch on the exterior to control operation.
Here is the inside. I cut the top of another 5 gallon bucket and secured it in the center of the dryer with 2x6. All of the 2x6 was cut with a 3.5 degree angle to match the rake of the bucket.
Without the top of the secured bucket I can slide in my other bucket and get a press fit. This allows easy removal of the tumbling bucket.
VIOLA!! And it will fit under my workbench!
Now if my SS media would get here......