I have a good friend & bow hunting buddy, who was a K-9 Officer for years, before they retired his dog, and he was promoted to Detective. I used to work with him and "Hudson" a lot!!! Tracking, Drug searches, Car stops, and "Big Sleeve" take downs. Numerous times we sprayed me down with the latest & greatest "scent killer" and odor eliminator products... Darn dog NEVER failed to find me!!!!!
I honestly belive, that those with success using them, were successful, because the wind, thermals, etc were favorable, and they would have been just as successful, without them.
Just one "old fart's" Oppinion.....