Neem will make your buds harsh and taste like shit if you use it the last month of flowering. Unfortunately, it doesn't prevent PM for more than a couple weeks, as new growth is unprotected. That means it'll manifest right in your buds.
GreenCure is much better, and can be rinsed off with a couple H2O2 foliar sprays- the last two days before chop.
The idea for controlling PM is to change the surface of the leaf (or other plant material) to 7. The PM remains within the plant, but cannot form the fuzzy/dusty white stuff on the plants that turns your buds to shit/poison. Neem,
Greencure, Baking soda, dish soap, organicide, etc, all do basically the same thing. H2O2 oxydizes the PM- killing the white stuff, but not the disease within the plant.
Eagle20 is a nasty chemical poison, but it'll kill the PM within the plant.
It is possible to run strains that carry the disease and never see it, and never send a patient away with contaminated medicine (that could send a spore-sensitive person to the hospital). However, if you're not willing to be dedicated to vigilance, start over or get out of the game, eh? :) Not being a dick; just ridiculously pissed at all the moldy meds out there given to unsuspecting patients.
Good luck; hope that helps.