Hmmm.... how about k-bicarbonate as a treatment? And I gotta say, Serenade doesn't seem to work for me. I mean, maybe I would have bud rot WORSE if I didn't use it, but I've still got it, which just pisses me off to no end. Driest summer on record and still with the rot.
What is Pristine exactly? Chemical/organic?
As a treatment, it will have some killing power but will NOT prevent any reinfection.... which will be quick.
I don't know why you can't goggle "Pristine fungicide" yourself?
http://agproducts.basf.us/products/pristine-fungicide.html