Deer are supposed to have better noses than dogs, right?
I have two coon dogs. I have watched them pick up scent off the breeze from a long ways off. One of my dogs was running down a gravel road one night, stopped on a dime and started looking up. Sure enough, there was a kitten coon 40 feet up a big oak and out on a limb that overhung the road. I have seen them "get a whiff" of coon a long ways from where it got hot enough to bark on. They can smell stuff just by riding by it at 40 MPH in the truck. Pick out a coon's trail from deer scent that's all around. I am always amazed at how well they can catch scent from amongst other scents. These two dogs can romp off over a mile distant, and if they lose the trail, they can come straight back to me by scent no problem. It's impossible to sneak up on them.
As a result of having seen this with dogs most of my life, I do not believe that a deer's nose can be fooled at all. Therefore I stay downwind or move to another spot where I can stay downwind.
I have been busted by a deer that were over 300 yards away in a good breeze. Watched it happen more than once, and that is after using unscented soaps, scent eliminator, etc. I am no longer anal about using products or scent elimination, but I am ten times as anal about the wind. If the wind isn't in my favor, I don't go.