I do have my anal moments and come bag emptying time might be one of them. I have Grizzly .3 micron bags on both top and bottom and after whacking them, there's still lots on dust sticking to the felt inside. I equate choked bags to diminished filtering efficiency so after strapping on a respirator, I shop vac the insides with the crevice tool. Just a once over, not trying to restore them to pristine white and I don't bother with this cleaning every time. I figure the better the bags can breathe the better I will ultimately breathe, and I want to keep doing this hobby for a lifetime.