Simple solution... any of our older, questionable, muddy or excessively dirty eggs I just hardboil, crunch up and feed back to the chooks... gives them some extra protien and calcium... especially if any of yours are going into molt like mine are...
My poor Sulmtaler roos tail is roached right now... looks like a dog bit off his whole tail... :/
Do just grind up the shell with the egg and feed it to them?