Update:
This fall most of indoors plants in my neighbourhood suffered from PWD,
I luckily escaped except for one Bruce Banner auto that I had to take 2 weeks early.
Most tried some sprays on this list with no success, I cannot say if they were properly applied…finally what seems to work for us and does not let PWD come back is a miticide with sulpher that can be applied as a spray (7.99 plus tax Home Hardware Canada) Sprayed plant in bath tub and left a fan on not directly on plant and in dark just before flip into flower. Left to dry slowly left a coating on the leaves. Only plants treated this way never had it return or had bud rot.
Myself, after the BB Auto fail, I bought this and left in closed room for a week after mixed in a large open pot, not sure if it helped as I am the only that tried but have had no PWD problems (knock on wood).
I also used spay as well.
Sparky