I actually tried something like that back in Alabama, just to see if it would work.
It didn't at first, although I did eventually find a way.
I had an old dryer with a bad heating element. I took a five-gallon drywall mud bucket, poured it one-third full of media, added a few hundred .223 cases from the ROTC range, pressed the bucket lid back on and fastened it down with drywall screws, tossed the bucket in the dryer, turned it on, and got away from the noise.
Came back when the noise stopped. The side of the bucket had cracked and the media was all through the dryer.
Bought a tumbler from Midway.
About six months later my sister wanted me to tumble some rocks for her. Not in MY tumbler! Pulled the dryer back off the scrap pile. Got another bucket, put in tumbling grit, rocks, water. Screwed the lid down like before.
This time I packed the bucket in place using blocks of foam rubber to keep it centered in the dryer. Turned it on. Minimal noise this time. Came back two hours later. No mess, but little change in the condition of the rocks. Turned the bucket sideways in the dryer and re-packed the foam. Noisier this time. Checked again after two hours. No mess, better tumbling action.
OK. Jammed the timer and left it for a day and a half. Came back and opened the bulging bucket - BURP! - and poured out the contents. Good- pretty well started on the tumbling!
Turned it over to my sister at that point. She showed me the results a few days later. Very nice!
-So it can work, if you think it through and don't mind making some messes along the way.