Twocrowsranch, I had read a chicken vet's thoughts on sour crop where he said not to do the ACV water. I had wondered about that since everyone says to do ACV water for sour crop. ACV is definitely not alkaline. The vet's statements would agree with what you have to say about the crop needing to be on the alkaline side. Also, yogurt is going to also be more on the acid side! What things do you use to get the crop back to more alkaline?It all depends on what is causing the sour crop to begin with. Many times it is an imbalance of ph and good bacteria in the crop, which causes a yeast/fungal infection. Or it can stem from an illness in the body somewhere to which the sour crop is a secondary issue. It can also come from a blockage in the intestinal tract.
Generally with sour crop, (and not impacted crops), something is always moving thru the GI tract. When the crop has gone "sour", it slows down. Rarely does it stop all together. So the bird will still move some material, and usually it comes out as diarrhea. If absolutely nothing is moving, then it could be a blockage further down the tract or in the crop itself.
But as the yeast infection grows, the crop slows down further. The crop controls how fast the food moves into the GI tract in conjunction with the gizzard. And when the ph is off in one of these areas, it slows the entire thing down. Crops need to be on the alkaline side and the rest of the GI tract in the neutral zone.