Once again, GC is spot on with this.
To put things simply, if you feel better wearing a scent eliminator, or cover scent, then by all means do so. I know I wouldn't waste my money on those products though.
Tflick is right about a coyote using all three senses coming in. They use them all to the max as well. If something doesn't look right, they will not come in. If something doesn't sound right, like a poor sound, or a meteal on metal sound, they won't come in...
But, given all the things are "right" for a coyote running into the stand, in most cases, if he smells you, it's like he ran into an invsible electric fence....He will be out of there at a run. If you use scent eleminator, he may well be a tad closer, (Or not) to you when he smells you and puts it in overdrive out of there. He WILL smell you though.
And if you use a cover scent, well, remember the McDonalds scenario....He smells bread, onions, meat and even the sesame seeds...and most certainly will smell YOU mixed with whatever cover scent that you choose to use. But he WILL smell you...
No doubt. You my confuse him with the other scent long enough for a shot, but maybe not.
If you don't think he will smell you, then you have not observed enough coyotes coming into your calling. Because if you have had many come in, you will see that they have that sniffer working at a dead run, and you can see it in their face & most certainly in what they do when they catch your scent. You better be a heckuva barker to stop them, or be good at running a rifle when they are flat out, wide open out of there.
All that needs to be done is have someone use whatever scent they wish, and start calling downwind for coyotes.
Be honest, and come back and give us all a report. If there's a product that can be documented to have the results that everyone expects about fooling downwind coyotes, I may want to invest in it, because it will surely be a top seller once it's PROVEN to be effective in fooling downwind coyotes.
In the meantime, it may be in the best interest of hunters reading this and wanting to kill coyotes to play the wind obsessively, and make your stand accordingly.
You can call with the wind in the wrong direction, but you'd better shoot him before he gets into your scent cone.
Barry