There are many types of wormers..... For lice,mites and most worms I use Ivomectrian inject able in a syringe an apply it to the skin under a wing or back of neck. But you do have to hold off on eating eggs. Safeguard is good for many types of worms and helping to prevent Blackhead disease in turkey and peafowl. Levasole is another good wormer. For Tapeworms i use Zimerctrian gold, a horse wormer paste and give only a small dab in the beak over the tongue depending on the weight of the chicken. Wazine is only good for round worms.
Ivermectin pour on is excellent for getting rid of lice and mites. Ivermectin kills many types of worms,including roundworms, but not tapeworms. Like chickenzoo stated, Zimectrin Gold does kill tapeworms,but only one kind of tapeworm. Valdazen liquid kills three kinds of tapeworms and is used for sheep and cattle. dosage is one half cc in a syringe for standard breed chickens and one quarter cc in a syringe for smaller breed chickens, it is given orally to the chicken. Ivermectin,Zimectrin Gold,Wazine,Safeguard can be purchased at a feed store or TSC. I had to order the Valbazen from Jefferslivestock.com