You may want to check with people over on the pheasant thread just in case. Wazine only treats roundworms, and chickens may get other worms such as cecal worm, capillaria, and rarely, gapeworm and tapeworm. Valbazen gets all worms, and is given just to each chicken once, and repeated 10 days later. Dosage is 1/4 ml for bantams, 1/2 for average hens, 3/4 ml for large hens and roosters orally. SafeGuard Liquid Goat Wormer is another good wormer, but to treat for all worms, must be given 5 days in a row. Dosage is 1/4 ml per pound of weight orally for 5 consecutive days. Wazine is easy since it goes in the water, but all birds should drink normally to get the correct dosage for their size.
Leg mites can be treated with castor oil or vaseline applied to the legs once a week and rubbed into the scales. Washing the legs in warm soapy water with an old toothbrush to loosen the scales can help before treating.
Ivermectin supposedly has lost it's effectiveness as a wormer due to overusage as a mite treatment.