Yesterday I cleaned my at work keyboard. I use a private das Keyboard at my day job. And over Christmas/New Year I carry it home to "un-dust" the poor thing. It is always kind of a surprise at first, and always a good feeling, when it's done.
So, yes, I take off all caps and clean them, but most importantly, I vacuum off whatever decided to hide in there. A particularly bad example is in the two pictures.
Highly recommended!
Cheers,
~ew