the best way to not have an abundance of snails is to rinse and examine any new plants, i won't buy plants from tanks at the LFS that already have snails visable. also, not all snails do the plague thing, the most common plague ones are ramshorns (red or brown) and pond/bladder snails.
apple snails and nerites don't do the plague thing. apples need male and female individuals in the tank to breed, and when they do they lay their eggs out of water so are easily seen and disposed of. nerites don't breed in freshwater, they will lay eggs, but the eggs won't hatch.
if you already have snails, adding to possibly well-stocked and an established tank to just get rid of one thing can not always be the solution. a bit of "a little old woman who swallowed a fly" thing hehe. when my tank was overrun with ramshorns i smooshed and picked out dozens and dozens of the little buggers until there were none left. it took about a month to rid myself, but it was easier than buying a fish that may or may not fix the problem.
.
