I just did an experiment and regular vinegar (5%) doesn’t even touch the rock. It bubbles a little but no real results. I even left the rock in there over night. Notta.
However I took a piece of plastic out of the tank and soaked overnight in the same strength vinegar and the shells of the snails dissolved totally. I would guess once dried the snails would die.
Plastic, vinegar works ok. Especially after drying.
Rock, wouldn’t trust it.