I can confirm that these helped me a lot in the greenhouse back in the days... Worked like a charm, although they never exterminated the mites completely, they ate most of them and was able to hold the rest at manageable population. Also, these are more for medium to low infestation, if its too far, its better to start with method that I'll post bellow, then wait one week and than let these predators in just to be sure
What I also did for bigger infestations, to counter SM, was boil tobacco (5 smokes for 1L water) for 2-3 minutes let it chill then strain it. Mix 1:10 with plain water and spray everywhere .. You can even do that few days prior harvest .. Just be careful not to spil that on skin, I got skin rush (and nicotine head rush as well
) ...Spray with it once every 3 days for 2-3 weeks and there will be none left.
Just my 2 cents in ..