Permethrin hen flea question

[Swiftbug2]

Got an issue with hen fleas and cat fleas ATM. Was considering getting permethrin for treatment of the hens. From what I've read Is to spray the fleas directly and also to make sure to get it on the chickens skin. Primarily on comb, vent, and under wings. What I'm wondering is how often to spray the hens? 7 day minimum like elector psp or what? Already started treating the coop and roost with other things

 

[Debbie292d]

It's just one time, then again in 7 to 10 days.