Interestingly, when I have had broody hens hatch and raise chicks, there were NO pasty butts. My theory is that the hen keeps the chicks warm in a somewhat humid environment, vs under a heat lamp, but I'm not sure why. Or maybe less stress on the chicks - well, undoubtedly less stress. What I've done with hatchery chicks with pasty butts is to get a little bowl of comfortably warm water and sit them down in it for a few minutes - just enough to cover the poo. They resist at first, but then almost seem to like it. Then you can really easily remove the poo with your fingers, it just kind of crumbles and dissolves. I've tried the warm wet cloth, didn't seem to soften it as quickly. Don't pull on those little butt feathers - the skin is super fragile and you can tear it pretty easily.