Oddly, I never thought of that Jestep. I went scouring through Target as my wife shopped and found silly putty in a plastic ball container. I just cut a small slit in the container and prestro, a concave surface to tumble pellets with.
If I went your route, I think there would have been less women staring at me as I scanned the pantyhose aisle looking for those eggshaped containers they used to come in. Apparently, they don't come in those anymore... or at least at Target. [emoji16]