All of the scent killer/cover products are nothing more than a successful marketing campaign and they make a lot of money from it. A deer has a nose far to powerful for any of those products to work. I've tried them and if I wasn't downwind, I still got busted.
Plus, if they really did work, you would hear of drug cartels buying it by the 50 gal drum to cover scent when smuggling drugs. Then, over zealous politicians would quickly have it banned.
Save your money to buy good camo or a nicer gun and hunt the wind. Hunting the wind has proven to be more reliable for thousands of years.