There was a post last year about this, some recommended bathes, others recommended pulling the feathers.
I had a BO with a pooped feather butt, and would not pull feathers and it was too cold to think about bath time…she some how took care of it herself.
If you can, try bathing it…but if you research the wash and dry, don't know how they would react.
Sounds too painful to pull feathers out, and would not recommend.
But trimming the feathers is not a painful experience. And that would be my choice. Best to approach after on roost for the nite. Chickens are more submissive then. But get someone to help and hold while you cut.