I had three adult does come in from the East yesterday morning, wind from West. Possibly thermals and I was in a treestand but trying to reduce human scent is always a positive. Not a pro staff or stooge for these but I washed clothing in Wildlife Research scent killer gold, showered before leaving with Scent-a-way max liquid body soap and shampoo by Hunter's Specialties. I like that enough to use it year-round and it has no added scent. The detergents have no UV brightners. Gimmick or science is your own perspective and there are many brands of products that I haven't tried or have never used. I set up that stand to play the West wind and cover the North and West but sometimes deer just don't do what I want. My thinking is spend a little and try them out to remain as unscented as you can. You will form your own opinions if you use them. I don't use deodorant though so maybe I should?
I just use arm and hammer unscented deodorant. Agree with what others are saying in that those scent free deodorants and other deterrents are just gimmicks. They can still smell you. Play the wind the best you can and always have your face to the wind.