I tip mine upside down and give it a good shake and gently (lol) and tap it on the desk a few times - then use the air blaster to get any stubborn bits. You CAN remove the keys to clean it out better and to clean the keys properly too but DO NOT remove the larger keys like Shift, Caps lock, space etc as they have springs under them and they are a devil to get back on again. You need to "pop" the keys up and off with something poked in each side of them - not a job for the faint hearted.

Far easier to shake/blast the bits out and clean the board & keys with a wet wipe or something similar.

C xx (whose keyboard is, frankly, filthy)