those little stingers are really not that bad to begin with and will only damage fry. I am never a proponent of chemicals, with all of my planted tanks I have plenty of pond snails and can never seem to irradicate them from anywhere so might as well use them. Yeah there a bit annoying but oh well ill deal especially now that I have found a use for them.
As for QT of plants, I always give my new ones a peroxide dip and quite often they spend about a week in a bucket to see what shows up. Granted I still put them into the fertilizer program but its not in a show tank.
If you want, I have two extra packet. I can send you one for free only if I can just put it in an envelope and mail it. I don't know if there is strict regulation sending drugs over the mail.