Yep, I've tried various soaps and all kinds of oils, tried regularly spraying down the leaves to keep them dust free and the humidity up, tried removing plants at the first sign of infestation, all of it seemingly futile under the literal avalanche of mites I get every summer. If I miss a few days of these preventative measures, my poor tomatoes will have leaves gone from a slight sign of damage to a fully webbed death. And it's not like my plants are water starved either, I use drip irrigation under thick mulch, so the soil stays moist even on the hottest days.
It's been really constraining on my growing season. I'm often able to get plants in the ground around mid-February and get a good harvest in May, but June/July is spent just watching all my plants die a lingering infested death. I'm in 10a, so I should easily be able to get a second summer crop in, but new seedlings planted at the end of spring seem to fare even worse than their established brethren. Hence why I've finally decided to spend the $$$ on predators, really hoping that their population establishes and tames the micro menace.