This and many similar products are designed to sell.
The first thing a deer will catch scent of is your breath.
Whatever "cover scent" you use, deer will still smell you.
Watch the wind and use an elevated stand and don't waste your money on gimmicks.
What I've learned from solely hunting deer from ground blinds...,
If your buddy's wife washes the hunting coat with a modern detergent, the deer don't like that perfume crap,
and will react if they are downwind from the coat, even in light rain. So to wash hunting clothes you use plain, unscented lye soap...., if all you can get is a bar of lye soap, then grate it into the washing machine and let it dissolve into the water before you wash the clothes. Remember....nothing with a "Spring fresh scent", and no cologne, no deodorant, etc.
For some reason the smell of wood-smoke on clothes is less offensive to some deer than plain human. I've had smoke smelling outer clothes on more than one occasion cause a buck to turn, stomp, and grunt in my direction when the wind changed, and the wind went from me to him.
I've been told to "smoke" my outer clothes by more than one venerable old deer hunter who say this scent is close to the musk of a mature buck..., but even if it's hogwash, if you must use a "cover" scent, at least wood-smoke is free.
I think that deer not only try to know if you're in the area by your scent, but also try to
range you with your scent. So I also scrape up the forest floor where I'm standing so no crunchy leaves or dry twigs are under foot, and it also kicks the smell of the forest floor into the air. (Just ask any K9 officer) So I think that if the deer smell forest loam, and wood-smoke, and the human scent that they also smell is fainter than the other two..., I think they may react that the "threat" is farther off than you actually are to them. So they are not nearly so quick to lift tail and bolt.
That's just my theory.
LD