Cone-shaped backflow incense cones that emit incense smoke in the opposite direction, that is, downwards, from a normal cone, is known as a Backflow Incense Cone. This is mainly because of the small hollow tunnel that goes through the center of the cone and ends with a hole at the bottom of the cone. What are Backflow Incense Cones and how does it work? The incense cones create backflow...