ORIGINAL: Howler
You can't hide your scent from a coyote, period!! Does it matter? Greatly! If a coyote smells human, it doesn't stand around trying to figure out how long ago the human was there, or how far away the human is, instead it begins to depart the area immidiately!
Can you wear enough cover scent to hide your scent? NO!! No matter what cover scent or how much of it you wear, the coyote will smell you. Period!!
When calling coyotes, always keep the wind in your favor and walk into the stand in an area where the coyote won't cross your tracks. Set up in a way that forces the coyote to expose itself in an open area before it can reach your scent cone, and then take the shot before it smells you!
If they can be compared to drug dogs at all this might give you an idea. A cop was talking once about how the dogs sense of smell works and how they can pic out stuff admist so many other things and it's because they smell individual scents. The example he used was that when there's a cheeseburger on the table humans smell a cheeseburger but dogs smell the bun, meat, lettuce, tomato, cheese, etc all individually.
Every time I think of scent control for coyote that comes to mind. Somebody correct me if I'm wrong please!