Assassin Snails are wonderful for the job, sorted me out no end. They will breed in the tank, much more slowly than pond snails. I do however have loads now, so only put in 1 or 2, and hope that they're not a male and a female.
There are other methods, though, you could try putting lettuce or cucumber in the tank overnight, then lifting out the snails.
Some would say that they serve a useful purpose - if the population explodes, you're feeding too much.