I have to disagree with a blanket statement, I've seen cover scents work many times as a drag. I could see the track I came in on and if I didn't use the drag the deer picked up my tracks instantly. If I used a Fox urine drag, they would cross or follow with no sign of 'alert'.
I also am a big fan of Deer Quest scent sticks. Shot a lot of deer, mostly bucks that are attracted to the scent from them.
One arrow shows the location of the scent stick..the other a downed buck.
https://i.imgur.com/5AxvM4Ym.jpg
They do work great when used properly and there are rutting deer near by.