Hello Sean,
My first reaction is why clean them at all? I suppose in a very dusty environment, dust may accumulate on the the woofer cones and the tweeter dome, and you might want to dust them.
I would use one of those pressurized cans of air (used to clean photographic lenses and the like) to remove dust from a tweeter dome (get it an electronics or photography store). You could lightly dust the woofer cone with a cloth.
I don't ever recall cleaning drivers, except perhaps dusting the cone of a woofer after using it with the grille off. I can't see how it could affect performance in any meaningful or audible fashion. Dust can't get into the motor assembly--the voice coil/magnet--unless the woofer dust cap were removed.
Unless they're incredibly dirty, leave them alone.
Regards,
