Your bottle label even shows that it is labeled for use on chickens. I am sorry the feed store didn't give your correct information.I was told at the local feed store I shop at the most, not to use it on the chickens. I will start spraying it on the chickens today. The local feed store told me I should use SEVIN 5, on the chickens and spray Permethrin inside the coop and run.
Mix a stronger strength for your coop and use 1.28 ounces per gallon for use on your birds.