Wuddup Nermz. I appreciate all the replies, even the one from the big man himself. Luckily yesterday I was listening to some old Co-op podcasts and I found the segment that I was talking about! Cory said that, after doing a small amount of testing, 1ml of Fenbendazole to 10 gallons of water was killing the snails in his aquarium, and was not doing any noticeable damage to fish, plants, or shrimp. For anyone who wants to listen to Cory talk about it, it was a podcast/livestream titled "What makes a good aquarium?", at time 23:15; uploaded to the Co-op podcast app on January 17, 2019. Again, at the time of the podcast Cory wasn't 100% standing behind this method, he just mentioned that it worked once for him.
Follow-up question after learning about Fenbendazole: It's pure liquid form is pricey online lol. Would an animal de-wormer or "fish-bendazole" work the similarly to Fenbendazole if I portioned it correctly? I realize the de-wormers might have chemicals that I don't want in my aquarium. Thanks for the help 🙂