Green spot puffers love them
Rid-a-snail and almost all the other snails be gone stuff are just copper. I would physically remove as many as possible then copper the system. Just run a low level untill you see the snails die off. After that do some water changes, run some carbon, and in a few weeks you should be able to buy ornamental snails again. ALWAYS look over the live plants when they come in. That is where in infestation almost always comes from.
If possible keep the live plant tanks returns covered with sponges to keep them out of the sumps. If it is real bad be sure to open the pump and clean out all the ground shell material out of the impeller.
HIH
S