i got a vibro tumbler from harbor freight for 50-55$ glad I did.. I like it better than the old rock tumbler I used to have long ago.. though I'm sure all of them work fine.
I run a mix of lyman treated cob media ( 18$ ), white rice ( 8$ per 25# ) and plain untreated cob media, fine ground litter type $?? stole some from the bag of cat litter when the wife got it home from petsmart.. BEFORE the cat used it!!