They are perfectly suitable for wet media without leaking however, I just bought a bag of stainless steel media from the guys in Orem Utah while on vacation. They specifically told me that it won't work in a vibratory tumbler. Has to actually tumble!
Both of my vibratory tumblers have a hole in the tub that the shaft comes up through to fasten on the lid. And twice when cleaning cases the tub vibrated loose and you say its safe.
And you want people to take your word and put water in a tumbler made in China. Don't get me wrong "MAYBE" there are vibratory tumblers that can be run wet. "BUT" if I did it with my tumblers, it would be "Death Wish 6" staring the dead guy.
And the instruction "WARNINGS" with my tumbler states "Do not use wet with ceramic, or water base media."
Signed the "alive" retired Electrician