I know that, as a Judge, if I saw any build relying on Dust of Sneezing and Choking as a primary method of attack, they would find my critique... sharp and dry.

First off, it's expensive. 2,400 gp per use. That's more than a Forcecage.

Second off, there's lots of things immune to it. Undead and Constructs spring promptly to mind, but also Oozes, Elementals, and a whole host of other things, including anyone with a Necklace of Adaptation.

Third off, it's right up there with Candle Gate Chains as far as Known Cheese

I doubt anyone could end up with higher than a 1 on Elegance, and it wouldn't significantly increase the Power score either.