I swear by Mighty Wash.
You spray your girls from head to toe, focusing on the bottom side of you leaves. I use a pump sprayer. Much easier than a trigger spray bottle. I spray once a week for 3 weeks. They'll be gone.
You also need to treat your grow space. When I was battling mites that were given to me as a gift (clones), I would wipe the shit out of the walls.
The lesson I learned was, always treat clones, that are brought in from an outside source (no matter how reliable) as if they are infested!
SH420