Agree, I think it is used some to help with hydration. Correct me if I am wrong. I can't remember for sure what I have read about that.Vinegar won't do anything against coccidiosis, or much of anything else. If they drink less because of the taste, that's worse.
How old are the chickens?I Have 6 chickens, different breeds, in small hoop. Gold Wyandotte has diarrhea with blood unexpectedly. May be this is infection? How to cure her?