Krosp, have you got a photograph of what the crop looks like? The previous thread that you have is in a weird format for me and it means I have to click and open every reply that has been posted and I am tired of it so thought I'd just post here.
I have a bird with a distended crop, she fills it with food and looks as though she has a big growth on her chest, but then when she is empty she doesn't look any different from any of the birds in the flock.
Anyway, I asked the Avian health lecturer at university and he told me that normally the birds with this end up with food that sits down the base of the crop and it starts to ferment there and causes a few big problems for the birds. He talked of doing surgery to staple the crop in bigger parrots which meant that the food carried on down the digestive tract as it should.
Without a photograph or reading all the individual posts from your last thread I don't know whether I am completely barking up the wrong tree but if this is what it is, I looked in an avian medicine book and it said that you can flush the crop via crop needle which will remove all the fermenting seed. It gave a solution to use to flush the crop but I honestly can't remember what it was.
If you would like I can go across the bridge to uni and check it out for you. Otherwise maybe try and google distended crop ... it may come up with something useful, but may also yield useless results as the internet often does.
If you need anymore information about it get back to me and I'll head across to the library and scan the pages you need.
All the best.