Can you tumble a rock short a utensils? ...
Answers: Nope. The kits mimic outlook, a single stone tumbling down the creek bed for years and years, sand washing over it, etc.
The kit are great, just set them up and forget them for a few weeks, ckeck, tumble some more, check, rework your polish grit, you start with rough grit and move about through a few steps til you get down to a polishing powder.
My rocks took roughly 6 months from start to finish. You get used to the swish :)
I suppose it's possible in notion. But it would be very difficult.