Incense (العود / Oud) has been used to get rid of demons, jinn, and other evil spirits for thousands of years. Yet none can explain exactly why burning incense works. It is unfair to dismiss the claim that it works (absent immediate results and due to the invisibility of the target entities) given that this tradition was central to the life of Ancient Egyptians, Chinese Dynasties, Native Indians, Muslim Sufis, and many others.
Here’s a possible explanation that I put forward. The best incense burns in blue color (e.g. blue Oud). Now remember that angels exist up there in the invisible ultra-violet portion of the frequency spectrum (blue sky/cloud association), while demons, jinn, the Devil, and evil spirits belong to the infra-red, the other end of the spectrum (underground). Burning blue incense is like exposing infra-red creatures to ultra-violet (blue) waves, and such exposure can drive these spirits from the exposure area. It is disruptive. It is known that light of different wavelengths does not add or subtract frequency. The effect is not from interaction, but rather from exposure or existence of an unfavorable light (blue.)
It is possible instead of burning incense, based on this hypothesis, to use a blue light at home to drive evil spirits away. This also assumes that the aroma of burnt incense is irrelevant to the invisible entity and that it is more of a sensory need for humans to experience the magic of the event. This is especially true that there’s no consensus on the smell of incense (sandalwood, myrrh, etc.) for effectiveness of evil spirit removal, suggesting a subjective human element.