http://www.inkmkr.com/Fish/FlubendazoleArticle.pdf
read and decide. That's the oldest write up and there are a number of newer ones.
I know you're against meds but removing the snail nothing else is at risk.
The treatment most miss all together is to worm or parasite treat our fish. We treat our dogs, cats, pigs, horses, cows,,, the list is endless. But not our fish. Not anymore for this fish keeper. Ick is a parasite.
I now start internally with all new fish and go from there. Since I started doing that I've eliminated the majority of weird things folks post about, including Ick.
Fish, plant and shrimp safe.
HTH