How long can halogen, xenon, and LED headlights last? These 3 points can prolong life

Regarding prolonging the life of car lights, there is an experience in the shop that when changing the lights, wipe the new bulbs with alcohol. Is this experience reliable? In fact, there is some truth, because when the repairman changes the light, he usually installs the lights with his bare hands or with tools, so it is inevitable to leave fingerprints, oil stains, sweat stains and so on on the glass of the lights. When the car lights are on, the working temperature is still very high. The uneven grease left on the surface of the car lights will cause uneven heat dissipation of the bulbs, resulting in local overheating and shortening the life of the bulbs.