Take a photo of your keyboard, then remove the keys, take some alcohol and a swab, and clean it then you place your keycaps again (see the photo so you know where to place them)
personally I strip my keyboard down, remove the pcb & electronics, and wash it in the bath, a light spray of silicon spray on the inside so it doesn't stick, and boom job done.
Compressed air can, if you can remove your keys and have some rough dirt you could use something like an old toothbrush to clear it, then just blow it out with the compressed air
Take off all keys, wash them thoroughly in hot soapy water then rinse. Then use a earbud/very fine cloth to clear out gaps in between keys. Did this on Saturday and it's 10x better now.
personally I strip my keyboard down, remove the pcb & electronics, and wash it in the bath, a light spray of silicon spray on the inside so it doesn't stick, and boom job done.
Simply remove all the keys but remember where they are layed out. Just use a air compressor following after with a rag and any cleaner for surfaces. Preferably you do not want to wash any of the buttons or the sort in water! Water is 1# of electronics.
Depends on what keyboard you have, there are a lot of good cleaning guides out there. I always clean my g15 by disassembling it and putting it in the dishwasher, works like a charm!