One of my 6 chickens has become very dirty for the past 1 month. She's otherwise healthy. I feel so sad looking at her because she looks so dirty! She has very dirty feathers. And her feathers are not shiny... I know that she did accidentally broke an egg and it got on her. This may be linked to that. Is there a reason why her feathers have become so dirty? is it safe to wash her? Any experience? Thank you in advance everyone! '