I have posted this a number of times, but I think it still holds true:I know some people feel cover scents have value, but one observation on the effectiveness of cover scents leads me to strongly doubt their utility. Years ago in the Yukon on a sheep hunt, I mentioned cover scents to my guide who had never heard of them. He laughed and related a story of a hunter he had guided on a grizzly hunt. They were observing a grizzly from a distance of about 200 yards with the wind in their face. The bear was feeding on an old rotting moose gut pile that was putrid and about two weeks old. Suddenly the wind shifted and they felt it on the back of their neck. Instantly the bear jerked his head up with rotting entrails hanging from his mouth, turned and ran like hell!
That bear was able to detect human odor from 200 yards away with a snoot full of one of the strongest "cover scents" I could imagine. I suspect that when a game animal smells someone with cover scents he smells the stench of a human mixed in with the odor of fox urine, or dirt or whatever.
I also read an article by Chuck Adams who has a lot of experience with scents. He also characterized the theory behind cover scents as "baloney". Adams did feel, however, that attractant scents did appear to work on occasion.