im not sure and this seems to important to guess on but for now ill at least bump it
a picture here would be extremely helpful because mildew varies widely and identifying the kind of mildew and te severity of the outbreak is key
my guess is that if i saw mildew i would immediately discard any suspected to be affected buds to stop it from spreading, i am suprised you say "still" in your quetion. This leads me to believe that you tryed to kill off the fungus or something which to me is long heard of, once you have mildew imo the battle is already lost
hopefully some one more experienced will pop in, a picture would probably help pull some one here