I use them all the time. I cut up alot of deer and grab every one i can from other hunters deer. I wipe them on my boots to cover my scent and hang them at my standsite. Ive also attached them to my decoy-visual+scent=mad buck!!! I also dab them in scrapes to make believe another buck has invaded an area. There are problems tho-immature bucks and does are often scared and on high alert when they get a whiff which often results in blowing/snorting. If a buck is with a doe that takes off hes goin too. Thats been the only real downside ive encountered. I also vacuum pack them and freeze them for use the following year and they smell the same as the day i cut them off. Hope this helps.
