Inappropriate use of insecticides over the years have caused immunity to many insects (not to mention health problems with PEOPLE and WILDLIFE) just like inappropriate use of antibiotics have made germs immune (again to the health risk of PEOPLE and WILDLIFE).
Go natural and use 1 tsp of Joy or Dawn (non-antibacterial-non-ultra) dish soap per 24 oz spray bottle of water. Turn your pot on it's side and soak the plants once a week. If the mites persist then alternate weekly with Neem oil mixed per directions.

What's more natural about spraying my plants with a man-made detergent that can eat the skin off my hands as opposed to a man-made insecticide which degrades in sunlight within a few days?

I've read that dish soap kills carnivorous plants--or that it is at least very difficult to use without killing them. Is neem oil safe for them?

watch this video about CP insecticides:

http://www.youtube.com/watch?v=lbRCdJ8ZNF0