How to clean the tweeter or woofers?

I use a soft artist's paintbrush or a Zwiffer cloth and if the dust doesn't come off with a very light pass I just leave it there. It's not affecting the sound, after all.

It certainly happens that people think they must clean them when there's no need. Spare a thought for the audio bumpkin! A pal of mine thought he had to take a little nub of something off his B&W's tweeter and wrecked it. It was an old model and original parts were no longer available. The off-the-shelf unit he found as a replacement was an approximate match for the design, and to top it off he now had two dissimilar speakers. He wound up having to say goodbye to his B&Ws before their time.