How old are they?
I recently gave my rooster a bath and was surprised to find he loved it.
I was giving him a flea bath so filled the sink to half his height with water the temp I would put a human baby in, with some of the flea soap as 'bubble bath'
He squawked a little when I picked him up and set him in the water but quickly changed his mind and sat down.
BE SURE TO HOLD UP THEIR HEADS!
They will try to lie down in the water like a dust bath I guess.
I poured water over him with a cup and let him soak a few minutes, then put him up on the side, drained the water and refilled with 'rinse water' put him back in, held his head up again, more pouring of clear water, a little feather massage to make the spa experience complete.
I pulled him out, wrapped him in a towel and then sat with a blow dryer on the cooler setting so I would not burn him (someone said they killed a chick once with too hot a setting)
dried him off and put him into a dog crate for the night so he would be completely dry before returning to the outside coop with the girls.
I think you can use any kind of gentle shampoo, like baby shampoo.
it's fun! take pics and show us.