If Dimilin is not available any organophosphates will work, Like Fenthion, Malathion, Trichlorfon, Masoten, Neguvon, Dipterex and Dylox. Most can be obtained at Home Depot (pesticide). Dimilin is the treatment of choice to treat branchiurian, crustacean and ergasiliid parasites.
PP is more for flukes and fungus which I do not believe you have and as Lupin mentioned it will burn their gills if not used properly.
PP is more for flukes and fungus which I do not believe you have and as Lupin mentioned it will burn their gills if not used properly.