Glad to see that your grow is going to come cross the finish line, nice looking buds I might add. this year has been a non stop onslaught of really bizarre scenarios for me. last but not least of which I'm still dealing with is powdery mildew in flower. I have some thoughts on the topic that may or may not be of some benefit to you. First off, I don't believe that eradicating PM is even feasible without a complete chop, evacuate, sterilize and start over, and even then there's a chance you will miss the one spore that starts it all over again. That being said I will tell you what I have done, #1 NEVER spray anything on your buds. full stop. I don't grow this stuff to be dumping something i have no idea what's in on something that one of my loved ones rely on for their pain relief, that goes for baking soda, potassium bicarb, peroxide,,etc... , etc.,, it wont eradicate the pm anyway. The best way for me to approach this beast is to make the environment unsuitable for the invader, with light, air movement, and ph, and temp. Doing this outdoors can be a bit tricky when momma nature isnt having any of it. Here's what i found to be true also, PM has no rhyme or reason,, but it loves the dark little spots that dont get full sun or good airflow, use that to your advantage. defoliate with caution and remember to treat every plant completely and wash up before moving to the next, I use a plant mister to wet the leaves I may want to remove, the spores can become airborne during defoliating and you don't want that, and remember what your seeing on the leaves are the fruiting body of the mildew it means that the PM has been around long enough to mature and repopulate which means you have a systemic issue, now, I know the experts say that PM isnt systemic, but I say that it is and it isnt, its neither, what the mildew has done is to extend its feeding apertures which are little tendrils down into the leaf structures to pull the nutrients form your plant. which sounds pretty damn systemic to me. this also can be occurring on either the upper leaf or the underside, or both depending on which species or subspecies of pm that you are infected with. What i like to do is mist the plant until wet, remove all affected foliage, then very carefully inspect the stem, usually where the branches come from or the leaf stem is where you will often see a faint white or fuzzy spot, I clean all of these with a damp cloth. I have done some experiments this year that I normally wouldn't have done had I not been so damn near perfect with my new cloning technique. and the results are in, the plants I treated this way have done a little better, but some that I did not treat at all that were far enough away from my main grow areas as to not risk infecting them , did better. and it wasn't just one or two. Marijuana plants if healthy can tolerate PM and not affect overall plant health , bud size, or bud density. I have a couple of plants that have all the white spots on leaves and even on the stems, and look as though they are not bothered the least, they are vigorous, healthy almost mature with huge buds and no other problems save for the white spots and some yellowing that may or may not be related to the PM. so,, is this something that as growers we are all going to have to deal with forever? was this a particularly bad year for PM? or all of the above? If you look around in your yard, in the ditch beside the road leading to your house, and at the land upon which your abode is situated, do you see PM growing on anything else? My answer was, holy shyt! its everywhere, so unless you plan on changing into your sterile suit every time you visit your completely sealed and controlled environment grow room, you may experience this problem. And had better equip yourself with the few things we know work. There are some great resources for finding out more about the plant specific Pm that affects only cannabis's or the ones that affect all growing plants online, just google it. not to plug anyone specifically but mother earth news has some great articles about the topic.