ARMOR All Odour Elimination Fogger Armor All Odor Neutralizer is created specifically for automotive HVAC (Heating, Ventilation, Air Conditioning) systems. Armor All FRESHfx Vent and Duct Cleaner Odor Neutralizer’s special formula allows you to treat vents, ductwork, evaporator core and drain pan area, helping to eliminate a variety of odors. It cleans by removing light dirt that resides in ductwork and dirt and dust that sits on vent surfaces.