Agreed.Aye. I'm struggling to think of anything that'll eat snails but leave your shrimp alone. Could try assassin snails as an alternative?
I have read that in a few places, never witnessed it though, and considering that my assassins are breeding and my shrimp population is still growing madly I think it's not that big a problem...but keep an eye out perhaps...FYI assassin snails can also kill shrimp. So when the carnage is over it's best to remove them.