I had the enjoyable task of cleaning a few butts that weren't so fluffy! I have changed to an all Organic Non-GMO food and it seems many of them are getting more drippy looking rear ends. A couple were downright nasty looking and I like to photograph my birds, so they needed a dip in the sink. Just as others described. I used warm water and pulled the feathers away from the mass of dried poop. I bring them into the washtub in the laundry room and have the water temp lukewarm and once they get it flowing on their behind...they settle down pretty well. I think it feels good to them. Anyhow...a little rubbing and scrubbing with lots of water rinsing and it only took a couple minutes per hen. I did two out of 3 that needed done today. Takes more time to catch them when they aren't feeling like being held than it does to clean them up. OH the joys of chicken keeping!