"Natural" preventions for Coccidia

Hello! I was wondering if anyone would care to talk about their experiences with not using medicated feed for the prevention of Coccidiosis. I am typically really skeptical of "natural" remedies which often, just don't work. I realize that this post may get people really worked up because people are passionate about organic/ natural methods and swear by them. Please, no rude comments or bashing, that is not why I go on BYC (honestly some of the other forums, things get quite ugly, it's shocking!!) I am not excited about feeding medicated feeds, but I have seen too many nasty chicken necropsies (autopsies) from chicks that have died from Coccidiosis (proven with microscopic examination of the tissues and fecal exam) to be quite ready to go "all natural"unless it really works. I get major anxiety when I am expecting a chick delivery, more nervous than I ever got having my own babies! So I can't willingly just take a chance on their health. I know hygiene and biosecurity are really important. But I had someone not want to buy my chicks because they were fed medicated feed She swore by vinegar for Coccidia prevention. Some people say oregano oil. what have you tried? does it work?