snail cull

I just picked over fifty snails out of the three tanks- for two different forum members who asked for them. It took a few days with long-handled aquarium tweezers to get them all. Tried a bait method I've seen recommended over and over- sink a lettuce leaf overnight and in the morning pull it out with all the snails that came to feed. It didn't work for me. In the betta tank I found the lettuce still in place- but no snails on it. Either they don't like lettuce, they fed and hid again before morning, or I don't have much of a population in that tank (hard to believe). In the 38 the leaf was completely gone- no idea. Did the shrimps and snails feed, then hide again? probably more likely that the serpae tetras tore it apart. Well, I won't waste my time what that effort again- it's just individual picking for me.