Haven't cleaned my keyboard in 4+ years. I use Zboard. They're so damn reliable ... unlike the other 5 or 6 keyboards that I accidentally broke. Zboard are detachable and cleanable. But well, there is nothing inside my keyboard ... Or let me check, I still have that air duster. Yup, only very little dust. Tho' I know what you guys are talking about since I cleaned the keyboard at my work. Hell, it was disgusting. Everything flew out of it. Zboard's keys are like next to each other so the dust and whatever else is out there doesn't get inside of it.
So next time to clean my computer is around Jan or Feb.