+1, I ordered the levasole(levamisole) from Charles too, one package less than the recommended dose, the worm disappear over night, have never seen them again in my tank.
before I ordered the levasole, I used pure fenbendazole 50-100 times more than the recommend dose for two weeks, both in fish food and water column, only suppressed the worm (or possibly wipe out the eggs) , but didn't kill the adult worm.
Oh NOO???? Really???? Scratch the above post... I am ordering now