BW -- we share the same sentiments on QDing when the car is a bit dusty (not dirty, as you point out). See my comments to Zav, below. (HEPA, heck, we need clean rooms, like they use when making computer chips; or the sort of bubble that the Boy in the Bubble was in - LOL). BTW, I really like the politenss of your responses. You just supply info or correct misunderstanding or clarify the point, rather than insulting the questioner.
Steve9185
-- Re your duster question. I have been really torn on using the Duster. I bought it a over month ago and did not use it. I started a thread on this site, seeking others opinions, while the Duster sat unused. About 60% said it was OK. Others claimed the Duster was invented by the Devil. Sal said that used properly and with care, it was OK.
I still hesitated. After much hand wringing, I started using it just a few days ago. I only use it if there is VERY light DUST (no dirt, nothing that is "chunky"). There is a very strong advantage. I can dust the car REALLY quickly. And, I suspect that dusting the sides of the car with the Duster, is safer than trying to dust the sides with a fluffy towel. And, I feel better about doing a Z6 QD AFTER I have brushed the light dust off the car. I do not want to be rubbing the paint with dust on the car, even with QD product. I just don't feel good about it.
I dust with just the TIPS of the Duster. I shake out the Duster after every two passes. So far so good. But, of course, that is what the optimist was heard to say as he passed the tenth floor, after falling off a twenty story building.
Hopefully, I will not be reporting disaster, but if it occurs, I will let everyone know.