You massage it in hopes of breaking the big mass into smaller sections, which will be able to be digested. I have turned chickens upside down, while pressing on their crop, to get rid of alot of fluid in their crops.........but you have to be careful that they don't aspirate. Some people feel you should never do it.
Sometimes what seems like a crop problem, is a problem further down the line.......maybe a growth or something they ate that they shouldn't have that is stuck. Some chickens just seem to have dysfunctional crops.
When you feel your chicken's crop, is it all soft and fluid-filled? Or can you feel a mass of food? Is the fluid smelly?
If you're going to massage, you need to do it at least 3-4 times a day, and be pretty aggressive with grabbing that ball of stuff and grinding it up with your fingers.
Is your chicken pooping?
I have found that scratch is horrible for causing crop problems. I quit giving it to my chickens, and only give them black oil sunflower seed for a treat.
