A couple of my hens have had impacted crop (I believe I give them sunflower seeds too much, so I have cut back some on that) and I could feel the sunflower seeds even though the crop was very tight and hard. If it didn't go down the next morning, I would then hold them in my lap, slowly pry the beak open and slowly squeeze the oil at the back of the throat. I wait a few minutes, then very gently massage it from the bottom of the crop to the top, then from the top to the bottom. I massage slowly about 3 full minutes, then let her go. I check back in a couple hours and if it is still very hard and packed, I give another massage with no oil, and I do it very gently. I then just wait until the next morning. Meanwhile, I don't put out any sunflower seeds for the flock so she can't eat any more. Usually, the next day, the crop is down and I still withhold the sunflower seeds a couple of days, then slowly let them have the seeds again. If they get the sunflower seeds a lot, they favor that over their feed. Just be careful when you massage and don't do it too hard.