Not a SA, well maybe a little, but this reminds me of a scene from the boyd coddington show when the shop forman told the boot to go out and shake the paint can until the ball stop rattling.

Personally gone through my share of argon gas cylinders and I have never heard that mixing ball banging around. Could this just be an old salt flat myth that folks sit by the campfire telling? Like grabbing 10 ft of chow line or a bucket of prop wash.