Is there any sure fire way of getting rid of a plague of snails?
I'd suggest against introducing dwarf puffers, unless you can provide them with a tank of their own. They're not strong swimmers, so require a tank with minimal flow to be comfortable.
You might consider getting a small tank in which to keep them, then drop the snails from you main tank in as food. They're voracious eaters! Water quality is very important.
Its highly recommended that they be the only species of fish occupying the water column. They are renowned for nipping at the fins of most fish - and they are pretty small so they make a tasty treat for anything with a mouth big enough to accommodate them.I'd read that Puffers need to be kept in a species tanks. Is that not the case?