There is a lot of funny comedy here.
But, for those that are serious, for a moment or new, You can't fool a Coyote's nose.. They only need 2 parts per Trillion to smell you.
To put this in perspective, you could put on a Chemical weapons suit with mask and wash down, and the suit would still give you away, as it's permiable suit and wouldn't be able to filter to the level of 2 parts per trillion.
With that said.. In my Opinion, based on everything that i have read and investigated. Coyotes have smelled people before, and while they get nervous, they don't solely hunt based on their nose. Mostly, but not completely. There are things that you can do to limit your scent you are leaving behind, but a spray that you put on yourself isn't going to cut it. There are certain weather conditions that are going to make it harder for a coyote to pick up scent. Some days you are going to be tougher to smell than others.
It doesn't hurt to work toward increasing a coyotes confidence and could be viewed as worth while efforts to use a cover scent. One of the best uses of cover scent, I have read about and used with sucess, is to have a spray that you spray a small burst into the air above the call.
I look for a stand where i have elevation advantage and a view. I try to have a place where the coyote that wants to come in from the down wind will have to expose themselves to get to the call and cross infront of me to get to the call. (usually at 20yrds from the call) I make sure that i can see the call and have a shotgun pointed at the down wind to be ready. I have seen the coyote come in following the sound and from the downwind. As soon as they hit that scent, it seems to confirm the sound with the visual decoy and they drop their head and run in.
But, in contest mode, I am not sure that i would say its something that you really want to take the time to do, as I am focused on getting in on the stand, set up quietly, and then getting out fast to the next stand.