I shined a flashlight into the horns of my Model 19's to get a good look at the bug screens and tangerines behind them and it looks like there may be some dust on or in front of the bug screens. I'm thinking that can't be good for treble to have to travel through dust. Some of you pro's may chuckle at my concern (understandably) and I'm thinking for pro sound PA applications a little dust on or in front of the bug screens may be the least of your worries. For home/hi-fi use, I'm thinking dust there isn't good (and in the words of Frankenstein "FIRE BAD"). Anyone else out there had too much spare time on their hands--obsessive/compulsive enough to worry about this kind of stuff and have any ideas/experience of how to clean the bug screens and area in front of them without clogging them/making it worse and without removing/disassembling anything and without hurting the frams/tangerines/drivers in back of them? FWIW, I listen without the grills in place so I've always worried about the presence of anything between my ears and the drivers/screens which now includes dust. OK, you "pro sound guys" can stop laughing now! (although I know most of you are into home hi-fi as well so are most likely accustomed to and not opposed to this type of knit picking)...