Depends what you're cleaning for.
If seasonal cleaning just remove all the keycaps and use cotton swabs drenched in isopropyl alcohol between the keyswitches and you should be good. I would advise not just using water because isopropyl alcohol evaporates faster and also likes to pick up a more mess than just water, hence it's used for cleaning thermal paste off CPUs as well.
You can give the keycaps a rigorous bath, multiple ways to do that but easiest is just to manually scrub the keycaps with some soapy water and your hands or a small hand brush.
You can go into more chemistry with denture tabs as this forum post suggests, though you could perhaps find better sources about this.If you want to clean the body (case) best you unscrew it and clean just the case manually while avoiding any electronics. You can really use whatever here.
Let the keycaps/case to dry by any means, maybe helped by a paper towel/towel/whatever. Avoid drying with sun as it might affect the plastic, and if you for some reason also want to dry the keyswitches (although you should really use isopropyl for this part) it will melt the switch plastic and make the keys mushy.
I would advise against sinking your whole keyboard in water despite numerous sources saying to do so simply because you can't be too sure about drying it off this way and it's easier to avoid an aftermath.
