Probably the bra hasn't been giving the crop adequate support. If the bra is supporting the crop correctly, the crop should be completely empty each morning. Just keep adjusting it until this happens.
Once the crop empties every 24 hours as it should, the sour crop should clear up.
Thanks for the update.
The crop should be emptying every night with the crop bra - if pendulous crop is the only issue. If the crop is still squishy in the morning, then she likely still has a yeast colonizing the crop.
If it responded the first time to the copper sulfate, then I'd got...
Chances are that installing the crop bra could help her crop empty naturally, and that will help this hen feel much better. She should regain an appetite and slowly regain weight.
Your hen may need to wear the crop bra from now on. Wait and see how it goes. She has been drinking a lot of water...
How old is Ruffles? I'm guessing she's beyond being a spring chicken? Usually, with repeated crop issues, there is an underlying cause, making the crop disorder a secondary issue. At this point, we don't know what that could be, but please keep it in mind.
A simple reason for repeat bouts of...