I've just gone through almost exactly the same issue with my 4 week old Blue Ameraucana. Key differences: age, no grass, no visit to a vet. Similarities: Emptied her crop twice, got maybe 1/2 out the first time, tried again after 24 hours, got most of it out this time. No foul smell either time. Like you, I isolated her (in a 55gal fish tank, towels, no pine, tightly limited food) for two days. Then, I put her with the others, and put them all on a feeding schedule all day Sunday. (Feeding every 90 minutes, taking the food away when the first bird turned away from the feeder). Thinking the impaction could only have been pine shavings, I provided grit, and supplemented the sick chick's food, and all their water, with probiotics and an enzyme blend. (I went to Walgreens and got "RenewLife Ultimate Flora 12 strains probiotic" and "Walgreens Daily Probiotic (one strain) With Digestive Enzymes" (Papain, Bromelain, Amylase, CELLULASE, Lactase, Protease, Peptidase)). Both products are powder filled capsules, I mixed them into lukewarm water at 1 cap each per quart. I also added ACV (2.5ml/liter) and Citric Acid ("True Lemon" packets I picked up at Sheetz, 1 pkt/liter) to their water, to discourage yeast. (I also provided a second water dish of plain water.)
The grit, and the cellulase, were the most important elements if the impaction was pine shavings. Emptying her crop allowed the grit to get down where it was needed, and gave her room to try to manipulate the blockage away from her crop outlet. Withholding food for 90 minute stretches motivated her to drink more of the lemon/enzyme/probiotic water, which should have helped loosen things up. (They all seem to like the lemon flavor...) Like yours, mine was ravenously hungry for the first couple of feedings after the second crop emptying. Gradually, I shortened the feeding interval, until I found the point where they weren't really hungry when I brought it back, at which point I left it with them. (My thinking here is that they're less likely to overeat if the food is plentiful.. if they're hungry and waiting for food, they'll gorge themselves when it's brought in.) Overall, things are getting back to normal.. my chick is no longer gagging, gaping, listless or dragging her tail - she is once again bright eyed, energetic, curious and affectionate. (Today she jumped up on my knee, then flew up to the top of my head, and "preened" me for 15 minutes or so!)
I have a theory: my impacted chick also has duckfoot. Her "thumbs" point forward instead of backward, so she's a little less stable on her feet. I think she was eating a bit more, just to provide ballast, shifting her weight forward to compensate for her misplaced thumbs. Beyond that, the more she ate, the more she stretched her crop, and the more she had to eat to feel full. Vicious circle.
Although she is my favorite chick (literally from day one, she has stood out from her siblings..), I made the hard choice that I couldn't justify a vet bill in the hundreds or thousands, to save a $10 chick. If she was a $1200 parrot, that would be different.. but she isn't. She'll get all the care I can give her, but beyond that, it's up to Fate and Mother Nature. Luckily, it seems like we're out of the woods here... I hope you're as lucky with yours!
I did read those articles a few days ago but her symptoms just don’t fit a sour crop or an impacted crop. If there’s no smell, could it still be sour crop? Her crop is soft and squishy and still parastalsing, so most likely not impacted. She’s very young and has had very limited access to the outdoors, so probably not parasites or worms. Any other ideas? Headed back to the vet tomorrow. Hopefully I won’t have to sell one of my kidneys to pay the bill! 
