As mentioned, your not going to fool their nose.
Your not going to ever be 100% scent free.
But I don't see any issues with trying. If you can make them think your scent is old, or there isn't enough of your smell to alarm them to bolting......whether you upwind or downwind...........great!
If you can afford it (the time and/or money), and it works for you, have at it. There is nothing wrong with making attempts to conceal yourself and boosting your confidence in the pursuit to kill a deer.
If it raises your 'game', makes you feel invisible to the deer, then it may actually boost your abilities to be a better hunter.
Not everyone can live in the woods, not everyone has more than a few weekend days a year to hunt deer. You have family obligations, work obligations, whatever it may be. You get in the woods when you can, and you may not have the opportunities to become well versed on deer movement, bedding area's, rubs and scrapes, gosh, then throw in the majority hunt on public land......well have at it with the scent products. Carbon clothing, machines, breath gum, whatever.
I do it. I take my body washing, clothes washing, equipment cleaning and storage as seriously as I can.
My investment: $25 a year in spray, $10 in sodium bicarb, $7 in soap/detergent, and some plastic storage bins that I already own.
The chance to get in the woods and my feelings that I am invisible to deer..........priceless.
I still enter and leave my stands as discreetly as possible, I hunt stands that I think the wind is in my favor, and if my regime makes me even 5% more invisible, i'll take it. The investment is worth the outcome.
Shaman's program works for him, Steve Bartylla (not a bad hunter is his own right) goes bonkers on scent control, wipes his equipment with peroxide, his bathing, clothes, etc ...its extreme. John Eberhart, probably the best most successful public land archery hunter in our time...sold on the carbon clothing. All three are good hunters with different methods, all 3 have a different method for scent control. All 3 have one commonality.
FWIW, I don't use cover scents, but I do use dried oak leaves when I store my clothes/gear. I figure I hunt in oak hammocks, might not hurt, plus the leaves are free .
"Go as far as you can see; when you get there, you'll be able to see farther."