I don't think the tank has to necessarily be dirty. All you need is a little decaying plant matter and a couple of snails will turn into several dozen. I keep hornwort and pennywort cuttings in a plastic tub under a plant light. I change the water about every third day, and after a couple of weeks I still will find some pond snails. This is in a tub with no fish food whatsoever. I've even soaked cuttings in water with no Prime and the little buggers still manage to survive. JMO but if you have a heavily planted tank pond snails are going to be difficult to get rid of entirely.Snails to control snail populations? Hrm ... might try keeping the tank a little cleaner too. Snails numbers are a good indication of how clean or dirty a tank really is. Lots of snails means - dirty tank.
I don't think the tank has to necessarily be dirty. All you need is a little decaying plant matter and a couple of snails will turn into several dozen.
As for what to do with the MTS after trapping, I hadn't thought of that... :huh:
MTS are a good addition to any tank, as they stare up the substrate releasing any trapped air bubbles.