Yur all missing the real problem. Yur best bet is to trash them and start over now while yur not far along. If all the clones came from the same place/mom then Yu will be fighting PM for the rest of the grow. Good luck preventin PM from growing in the middle of buds and even more luck smokin/selling those buds.
IMO and as far as i kno, yu cant RID the plant of PM. It lives in the plant. It will pop up whenver and wherever it can and spores will spread. Before it gets out of hand, scrap them, clean everything, and get some good reliable clones from someone who has a clean set up and fresh clones. Trust me. DO NOT BUY SHIT THAT CLAIMS TO CURE OR RID YU OF POWDERY MILDEW!!! Why invest in crap to spray on yur plants for the duration of yur grow? Not to mention any clones takin will have PM. An eventually yur grow room will be riddled wit spores so any new plants introduced will be at risk.
Scrap, clean, start again.
Sir KK