See, I'm that weirdo that cleans each and every mouse I come into contact with at the University because I can't stand dirty mouse movement! I take the roller ball out and scrape the gunk off the directional rollers inside, then put 'em back together (my only OCD ideation! lol) I must say my optical mouse was a great improvement, but I even clean it about once a week or so, along with the ones in the computer labs on campus, because the glide feet get gummy and tend to stick to the work surface. I find that my mouse here at home doesn't track properly on my desktop, I have to have a mousepad underneath (has something to do w/my desk being black semi-gloss surface, doesn't reflect light into the optics very well)
It's pretty much the first thing I do when I sit down to a strange computer. I went to a good friend's house, and did this out of habit, while she was in another room, thought nothing of it. She sat down after me, and asked "What did you do to my mouse to get it working again?????" (It was gummed up pretty bad inside, she'd been doing the ol' jiggle n shake technique for a while) She had thought it was broken, and was going to have to buy a new one!