I can't speak of scale but the white fluffy things sounds like mealy bugs.
I use 70% isopropyl alcohol and a few drops of dish liquid mixed in, sprayed on them. I use it straight. Others dilute it. I think mealy bugs have a 5 day incubation period. When mealy's get soaked by the alcohol, you can see them change color from white. I believe that means curtains for that bug.