Well I've tried a few of the sprays and I really like em. The clothes---too pricey for me. But the sprays have worked well when used correctly. I've had all sorts of critters downwind of me without them spooking.
Correct use though, is all about how diligent you are. No spray in the world is going to help you if you climb 4000 ft after you use it and are sweating *** off. If ya want it to work, you have to apply it correctly, make a point NOT TO SWEAT, even if that means that you walk in under-dressed and cold, and re-apply every now and then as you feel it's needed.
I'm mainly talking treestand and stalking here. Those of you in high elevations may never be able to employ it correctly because of the miles that you have to cover.
Typical scenario for me:
When I get up in the morning and begin getting dressed, I spray each layer of clothing once it's on my body. Then after I'm MINIMALLY dressed, I spray each layer that I put in my backpack as it goes in there---spraying the inside of my backpack first of course. Once all of that is done, I spray my rifle, bow, whatever I'm using and any and all accessories, like binos, rangefinder, etc...
Once I get to the place that I'll be hunting, I spray lightly one more time to get rid of the odors that I got on me from the drive in my truck. Then I slowly begin the walk to my stand or where I'll begin my stalking from. Once there, I let myself cool off completely so that I'm cold. Once I'm cold, I change my socks--spraying the first pair before putting them in my pack. Then, I dress for what the weather is that morning.
I've had deer downwind of me many times and totally oblivious to me. You may not believe this, but I even snuck up on a bedded coyote once in fresh snow---downwind!
This stuff CAN work. But like everything else we hunters use, it's only as good as it's application. If you CREATE more human odor than you cover up/eliminate, then no product will ever seem effective.
As for the cigarettes, gasoline, diesel fuel, etc....not one of them will scare a deer away if left in a field all by itself. Mix any of those smells with human odor though, and the human odor will.
We as hunters would do good to remember that animals smell in a different way than we do. If we smell beef stew in a pot on the stove, we just smell stew. If an animal smells that same stew, they smell the beef, the salt, the pepper, the corn, the onions.......they smell everything individually and can detect THE RATIO of one smell to the other.
This is where scent elimination comes in. We'll never eliminate ALL of our scent unless we hunt inside of an airtight container. However, our goal should be to radiate such small traces of a smell, that our critters think we're still a long ways away from them. If we smell like were 800 yds away, but we're only 75 yds away, the scent elimination product(s) that we used were 100% effective in what we asked them to do.