direct 95-degree sun for half a day. Warmth is fine; cooking the plastic is not. If it is already hot outside, a bright laundry room or sunroom window works better.
10. What this trick will and will not fix
This method is excellent for removing surface yellowing from grease, smoke residue, dust buildup, and storage grime. It can also improve age-related yellowing enough that the fan looks fresher and cleaner from across the room. On older off-white plastic, I often see a difference of one to two shades after a
