is surface grime, which feels tacky or dull and usually comes off with soaking. The other is deeper discoloration inside the plastic itself from age or UV exposure. My grandmother’s trick helps a lot with the first kind and can noticeably improve the second, but it may not return every blade to bright factory-white. I think it is still worth doing because even a 50% improvement makes a fan look much cleaner.
2. The “0 effort” trick my grandmother used
Her method was simple: take the fan apart just enough
