what yur doing is good, if u just have a few plants that yur depending on, then u have to keep spraying them..its a constant fight, you just have to stay vigilant. The best you can do is control them in the flwr area, and hopefully prevent them from getting to your veg plants.. sprays can keep mites in check, but wont totally eradicate them for good.
i havent tried Forbid, but if it works, I think it'll be a good tool to have, as a last resort for salvage purposes..
For larger gardens, the only sure-fire way that I know to get rid of mites, is to scrap the entire garden. throw away all plants and medium. scrub everything and room top to bottom with h2o+h2o2 +bleach. Beethoven and then dont grow for at least 2 weeks after.
U could try dip/drench some branch tips in neem or chrysemum oil or something, a bunch of times over a several days, and try and get one shoot u can clone that's mite-free.. then from that one clone, u save yur genes..
If u have time and money to burn, then you can remove the really bad plants, trim and prune the remaining ones. flip off yur HIDs, hang some flor shoplights, and cut off ventaltion. bomb the heck out of yur room with Beethoven and hang a ton NPS.. you'll still have some issues,like eggs surviving a hatching later on; it'll be a constant battle no matter what, unless u 86 the whole garden..
the possibility of shit-canning a run at any given moment during summer, is why its best to keep duplicate genes in multiple locations. u can do this on a small scale and even in the same building.. yur couple of plants flowering in a closet, along with yur veg plants, at one end of the house, and a few backup clones under a cheap 9w led in a cupboard or something at the opposite end..