The pesticide companies can test their products on bugs, and if it kills a few, they can legally say it kills them. Even if it does a poor job of it. You really want a specific miticide to do the job. Good ones are not cheap, but very effective. I use Floromite SC.
A 4 oz bottle will cost you around $50, but the mix ratio is very small. Between 1/4-1/2 teaspoon per gallon. So, you get quite a few rounds out of it. The residual effects are good for about a month.
Neem oil is somewhat of a deterrent, but at the cost of completely obliterating your plant. I never really had luck with it personally. Especially if you have an infestation.
