Having just gone through this with a young rooster I can only suggest that you read these links and do as they suggest in trying to empty n clear the crop.
My Rooster cloud was so severely impacted that I was only able to shift a small amount and of course this happened over a weekend when the vets closed. Well I kept what was in his crop wet and massaged it and he was able to eat a little hard boiled mashed egg. I also gave him some vitamins in water to drink. But by Sunday afternoon he quit eating and his comb went very pale he also became pretty weak and unbalanced. He lost a lot of weight in the week and a half he was out in the stables.
So Monday morning he was into the vet's first thing. They put him on a drip to boost his fluids etc. then flushed out his crop and repeated the flushes through out the day. He stayed in at the vets for 2 days and they repeated the flushing again a few times on the 2nd day. By the 2nd evening he was wanting to eat again and chatting to people.
I collected him this morning and though under weight and weak he's been given a clean bill of health and is worm n pest free etc. He's got to stay in for a week or so to build up weight again and for the next few days he's got to have his crop massaged several times a day. His food also has to be wet now.
I hope the links help and there are some good links on you tube to watch how others clear impacted crop.
Let us know how you get on with your chicken please.