Iowa DNR has accepted the fact that the cougar has a rightful place in their ecosystem but disagree that they be listed as a furbearer. They are a big game animal and should be listed as such.
Once listed as a furbearer as time goes by they will then be able to use trapping as a method of harvest which I disagree with. I support trapping but not of such a large animal.
Trapping is non-discremetitive. They catch Toms, females juveniles and young. There is no way to sex a trap. If you get a female that is lactating caught in a leg hold or snare, who is gonna release that animal? You will essentially kill the female and all her young this way. Hound hunting is the only form of selective catch and release when hunting the cougar.
This is just an opinion and hopefully will not offend anyone.
When it comes to scent, there are basically two types; those that attract and those that mask. I've tried both on many occasions. There are lots and lots of "doe in heat" scents, designed to attract a big buck into range. I've also used a "cow in heat" scent while elk hunting.
Another scent would almost be better named as a "coverup smell". The main goal is to cover up human odor or mask it. Though I don't believe you can ever totally eliminate all human...