I kept a few yoyos for a while back when I had a pond snail population explosion. I couldn't tell that they made a dent in the population much but I didn't notice any fin nipping. I have found that assassin snails work extremely well for controlling the snail population but I can't seem to keep many alive for very long with the levels of CO2 I run now
It takes quite a few assassins though to effectively control the pest population. I used 12 in my 30 gallon.
Assassins are really pretty. I read that others had horrible experiences with them exploding in numbers too. And then once all the food source (other snails) were gone, the Assassins die and when all is said and done, the substrate is littered with snail shells.
I guess the best option for me is to just continue collecting them by hand.
Oh well. At least they aren't gross.
I would try the Yoy loach for its beauty, but man I would hate to try and catch them in my jungle of a tank if they did start nipping. I would say that was one positive of the old scape (nearly empty). I could experiement with fish and easily net them if they became a problem. Those days are long gone. No regrets! I love my plants!!!