I think the most important thing about coccidiosis is knowing how to avoid the chicks getting it in the first place, then the question of remedies doesn't have to arise. As I understand it, coccidiosis can develop where the litter in the brooder is damp, eg around the drinker, and conditions in the brooder are less than scrupulously clean. If the chicks peck around in damp, dirty pooey litter, they pick up the oocysts which cause the gut infection from the droppings of already infected chicks. It is thus very easy for it to transmit from one chick to another, but can be treated, if diagnosed early enough, by adding Coxoid to the drinking water and of course cleaning up and drying out the chicks' environment and making sure they are being kept warm enough but not too hot. When Coccidiosis has occurred it's necessary to disinfect the brooder and all equipment with Bi-oo-cyst disinfectant, which is pretty strong stuff but specifically designed to deal with the oocysts that otherwise might remain lurking to cause re-infection down the line, either to the current brood or the next lot to use the brooder or equipment. People hatching chicks really need to have these preparations in their first aid kits, so if required they can be used immediately, without delaying until a trip to the shops can be managed. It may originate in the incubator, i expect, so scrupulous hygiene before the hatch is also essential. Of course accidental outbreaks can happen even to experienced and careful keepers, but coccidiosis is largely a preventable disease caused by poor management, and I think there should be no need to routinely give healthy chicks any kind of supplement or food other than fresh chick crumb and clean water, changed frequently. Probiotic yogurt is indeed wonderful stuff, but I think it must be messy to use in a brooder, and dipping chicks' beaks in it would possibly introduce milk-based bacteria to their environment and this might in itself have unfortunate consequences