I know the clown loach is always the popular one to offer up as the solution to snail problems and they do grow slowly after the first year but in the end you'd need a minimum of a 50gallon tank for those fish.
Nearly ALL botia based loaches eat snails. Skunk (botia morleti), Sun (botia eos), yo-yo (botia almorhae), Tiger (botia hymenophysa) will all eat snails. I would guess (from general construction of the mouth) that nearly all the botias eat snails (such as modesta, and whatever other dozens I missed). The ones I list in the second sentence I have personal experience with.
Aggressive tanks should use hymenophysa or modesta. Semi-aggressive tanks can use morleti, eos, almorhae, and clown loaches. Peaceful would probably be best with morleti, almorhae and clown loaches BUT you have to be wary of how you stock the loaches...if an "alpha" loach develops out of your group it will become aggressive towards other fish in the tank. If you have peaceful bottom dwellers (cories) I'd only recommend the almorhae (not sure on clown loaches and peaceful bottom dwellers cause my 29gallon can't support a clown loach so I don't even bother with them).