how do they work if you should be downwind where you expect the deer to come from? the smell of the lure is going to blow the same direction your scent is blowing.

I have never had much luck with lures. I find that bathing/showering with scent free soap, washing you outfit in just water, and trying not to contaminate your area with your human scent works the best. I bush hunt, this usually means if they smell anything out of the ordinary, they are gone(except the dumb ones).
I have also found that the wind is usually your friend if you are trying to call the animals in from an area upwind of your stand/blind.

If your scent control system is working you should be able to be set up between the scent and the deer' s expected arrival point , or somewhat to the side of the scent stream .