I wear out cheap keyboards so I get the expensive KeyTronic keyboards, and if they get sticky I give them the full wash treatment. Pop off all the keys, disassemble the whole keyboard, give the keys a separate bath of their own, place the plastic key holder assembly in the washing machine, and let it be washed right. On modern membrane style keyboards, the actual active circuits are really nothing more than two printed circuits on flexible plastic, separated by a spacer sheet. Dead simple, and they don't actually get dirty inside in normal use.
Keyboards do acquire an amazing amount of crap. If anyone ever is to be investigated by the police and they need your DNA evidence, they can get plenty from your keyboard even if you DON'T surf internet porn.
CJ