Do not empty the crop. Wait until tomorrow am to check the crop to see if it is empty. Emptying a crop can be very risky to cause choking, even by experienced people. Sitting puffed up or hunched with the neck into the shoulders can be a symptom of generally not feeling well, but is common in coccidiosis. Feel your other chickens’ crops throughout the day to see what is normal. ,Here is some reading about how to identify and how others deal with crop impaction or sour crop:
https://www.backyardchickens.com/ar...w-to-know-which-one-youre-dealing-with.73607/
https://www.backyardchickens.com/ar...w-to-know-which-one-youre-dealing-with.73607/