Just curious.
Why pressure wash then bleach, instead of the other way around?
When I paint, I spray bleach (50/50), then wash. Then, I'm painting a clean surface. Mildew residue and buildup is my biggest concern.
Will bleach leave any residue that may react with paint or stain? Or does it "dry up and blow away?"
What about the "objects" of the bleaching? Or are you bleaching for coloration effects only?

(I'm not a painter, so I don't know right from wrong.)