Either dimilin or trichlorfon will work. Both medicines are toxic so handle them with care. Use gloves when you treat. By the way, trichlorfon comes under different names so check the labels carefully. They are labeled as dylox, neguvon, masoten, metriphonate, etc.
Please be sure to get your iodine solution/mercurochrome/betadine. You need it. Get forceps or tweezers and grab each anchorworm dangling on your fish by its head buried under the epidermis of the fish. Get a swab of cotton and douse it with iodine solution. Apply it on the fish's wounds. You need to remove the adults or you will have to dose the treatments at a higher concentration instead. I advise removing the adult parasites so you will deal only with the emerging juvenile and larval stages.