I figure a lot of 'hunting stuff' that's being sold these days is like fishing lures... to make money, they don't have to catch fish, as long as they catch fishermen.
I think the scent-blocking stuff is a bunch of baloney, and spend my hard-earned money elsewhere. I wonder... could a guy eat a big pot of chili and beans, pull on a pair of those activated-carbon pants, and then pass gas that came out smelling like the autumn breeze? I doubt it. But I could be wrong. Even so, the way I figure, a person would have to be covered from head-to-toe, to keep scent from leaking out anywhere... like the opposite of a radiation suit.
I bathe as much as possible, use scent-free deodorant, and wash my hunting clothes regularly. That's it. I'm not the most successful hunter, but have had plenty of up-close deer encounters just by playing the wind right.