For it to work it needs to be unpasteurized, since once you cook it the best bits are dead. Heat treatment to kill bad bacteria also kills good bacteria. Organic is usually best but I am suspicious of what they're using on some crops instead of normal pesticides etc, as I know on some crops they use something my animals don't like... Overall ACV is quite beneficial though. I don't give it as a staple though a lot of people do, I don't because it's pretty expensive here.
From the symptoms you're describing it doesn't sound like wry neck to me, as that's usually characterized by sideways twisting (that may also go under the body), and usually involves lameness, not running around backwards. I have once heard from a quail breeder of an almost identical thing; this person, like some other poultry breeders I've met, is unfortunately of the opinion that inbreeding 'doesn't matter' with birds, only mammals. (Like the majority of those with bizarrely ignorant opinions on birds, they seem to have gotten this garbled info from misunderstood and junk science documentaries that confuse and misinform more than they teach, unfortunately). So anyway, they have bought an initial batch of birds, usually brothers and sisters, and just kept breeding and breeding for however long it takes for the birds to stop hatching altogether.
Anyway this quail breeder had birds who would run around normally, eat and act normal, then suddenly their heads would go under their bellies and they would run backwards. When it stopped, they went back to acting normally. These quail breeders kept breeding from these stock as they figured it didn't matter. I have heard of this happening due to inbreeding in turkeys/chooks/quail but not happening due to diet, but that's not to rule it out. If it is due to diet and not defective genes causing spasms, then correct diet will hopefully fix it. (I obviously can't guarantee it as I've never had that problem so have never treated it).
I would view this as a positive, since anything you use to cure the bird of the spasm will likely work for other problems involving spasms, including on yourself or other animals (if it's a natural cure, that is). If you're trying natural methods it may help to try the natural chook keeping thread. I'm not dismissing all science or documentaries, either, just those that are made by uneducated profit-oriented people who think it's OK to make new documentaries repeating 'facts' that have been discarded by science since I was a small child. Even as a child I could pick a lot of the untrue 'facts' being repeated in these rehashed money grubbing (often taxpayer funded) docos. Researchers for these docos relied on their childhood animal books, not the new info available.
Best wishes with whatever you choose and please keep us updated.
