Help! Chicken needs a clean

[Prettyinpink]

Hello, I've only had my silkies 3 days so they are not tame yet and are still very wary and scared as they are only 5 months old but the problem is they have dirty bottoms and I don't know how to deal with it or how to help them. I'm very new to all this so I need any help or advice you can give

 

[Boise-girls]

My banties are older than your silkies, but aren't used to being handled. I got them as free-ranging adults. I had one with a poopy butt.
Following advice on this forum, I waited till they were sound asleep, then (with a helper) took her from the roost, held her like a football under my arm, and worked on her butt. A damp cloth didn't do much, so ended up carefully using scissors. Some people do a bath, but probably not practical for yours.