If I had 65 chickens I wouldn't be bathing mine either- no matter what color they were--LOL!!!. Guess, what I'm saying is there's no way I'm bathing 65 chickens. Thats why I got red chickens can't see the dirt LOL.
I have 5 so it really is no bother -I do like to keep their feet clean so about once a week I do soak their feet. They are a year old so they are pretty used to it.