I thought this was a great place to start because it was pretty dang cheap! I believe it came in under $5. I noticed after spraying that it gave quite a gray overcast to the roots. Typical for dry shampoo (so I've heard) so I just brushed it out as the bottle instructed. Initially I thought well that works "ok" but within minutes I noticed it didn't really soak up the oil like it's supposed to. In fact I went online and did some more reading about it and I read that people ended up using this as a way to add texture to the hair (i.e. adding something for the clean hair to hold onto). So basically the exact opposite result from what I want from dry shampoo. As my sister-in-law would say, "Bum-Diddles!"
In this corner, trial #2: John Frieda Luxurious Volume "Anytime Volume Refresher"
And in this uh... er, other corner I guess, trial #3: Batiste Dry Shampoo