Long story short....shit doesn't work for shit. I've been trying different methods of using it for about a month, and I haven't gotten acceptable results ever. For example, today I washed my hair with just apple cider vinegar (which I do sporadically to rebalance pH/strip out impurities), and after drying my hair noticed it looked a little greasy still. So I followed the directions, applied the dry powder, distributed it through my hair, and brushed it.
It semi-works when you first put it in, as in it made my hair look less greasy but also more dull. Then an hour later (once I got to work and need to look decent, naturally), it is now back to pre-shampoo status greasy. No bueno.
I've gotten great volume and clean-looking/smelling hair from other dry shampoos (my favorite 'dirty' shampoo, aka nasty chemical-full, was Suave's with keratin, and I've had good success with Lulu's dry shampoo, which is clean), so I know it's not just an urban legend that dry shampoos work. Unfortunately, Acure's does not, at least not for me.
If you'd like to give it a go, know that my hair is fine but there's a lot of it, and although it's not super greasy I can only go a day or two in between washing. So if those characteristics don't apply to you, try it out!