just a few months ago my boss had a problem with spider mites on her Lucky Bamboo plant in our leasing office... SNS217 is a godsend... ONE good heavy treatment and they were gone, havnt seen a single one yet and its been almost 4 months...
iv also used the SNS217 so my MJ plants and since there is far more surface area and nooks for them to hide it took me 2 treatments 10days apart to cull the spider mites and finally be rid of them... as THG said SNS217 (miticide) to take care of the bulk since its a "direct" spray... then use SNS209 to keep them away, SNS209 is a root drench that works to get rid of many many pests we hate in our grows... it works by basically infusing the soil with organic goodies that the plant takes up via its roots and basically fortifies the plant against the pests from tippy top to the bottom most roots... the SNS 209 is a systemic insecticide, meaning it works from INSIDE the plant rather then on the OUTSIDE like SNS217...
iv also used AzaMax by General Hydroponics, its not an organic insecticide, but HOLY COW does it work like a charm... if your infestation of mites is REALLY REALLY bad and the plant has a good healthy, well established root system then id say go a round or 2 of AzaMax, its a little more expensive but it can be used as a direct spray right onto the plant and as a root drench to kill what ever is in the soil too that you dont want, but if you go overboard and dont follow measurements and reapplication times you can harm your plant, but if the infestation is really really bad AzaMax works like a charm, and quickly...
personally iv ran out of SNS209, but i still have half a bottle of SNS217 and half a bottle of AzaMax on hand in case anything should happen... always good to be prepared and not need it then need it and not have it...