I like ACV. I spray that stuff everywhere as a cleaner. It reeks but the smell goes away soon, and leaves a film (w/ the mother & acetic acids) that keeps fungus from growing. Kills PM too, and is natural like citric acid.
You could dunk the smaller clones upside down in a more concentrated solution of diluted apple cider vinegar (or citric acid water, etc) and rub all the leaves to really smear it in, for a much better application than spraying. Don't make it too strong though, be careful. That stuff will strip the mildew right off your shower walls, or the foot fungus right out from between your toes, lol.
You can't really do much once your in flower, without coating buds with anything. Even if you only spray the leaves the best you can, there's still gonna be mildew ending up in the buds, even if you don't see it. That's the main reason to start over I guess... If your in veg, it might be worth fighting for?