I oftentimes hand a small battery powered ozone generator out of the window of my elevated sportsmans condo on the downwind side. I don't know if it helps or not, but I can't smell any ozone inside the stand and I see no negative reaction from downwind deer. I'm probably wasting my time, but I think it might help prevent some of my leaking scent being as noticable...Will they block scent? Oh yes! Are they dangerous to be around? Oh yes...