I just used Eprinex pour on for cattle. It is not advertized for use on chickens probably due to lack of money for testing but it was mentioned here on BYC. Found it at Dells in the cattle section. It wasn't cheap but worth it since there is no egg withdrawel (or milk or meat withdrawel on cattle) and it should last a while. My reserch on BYC turned up a dose for chickens of 1/2 cc for large fowl and 1/4 cc for bantys. Applied to the skin at the base of the neck. It worms them and takes care of lice.
So thats going to make 40 chicks in the bathroom.. Oh oh my bathroom his huge almost the size of my kitchen... Wish my kitchen was bigger.. ok ok talk to you later. Have the kids for dinner tonight lots to do today..