I must disagree. I normally clean my fans before switching spin directions. Our living room doesn’t get good circulation compared to the rest of the house and so the fan is on a low setting pretty much 24/7. I was thinking the same as you, it’s been moving like non stop since last time I switched directions, how much could have collected? A lot apparently. Once it stopped and I switched directions and turned it back on- dust went everywhere. I had to vacuum the entire room and couches. Learn from my mistake. Moving fan blades does not mean clean fan blades.