If you have a detached keyboard, you can TOTALLY disassemble them and clean to your hearts content (an excellent task for the Obsessive Compulsive in your life ... gotta get all 104 keys just so!). Use a liquid dish soap or window cleaner (with Ammonia D!) and rubbing alcohol (great for ink stains!) and keep the water away from the little circuit board / chip inside. Other than that, it's all plastic & rubber and mylar ... nothing a little water will hurt. You can even put the keycaps back on in pretty much any order you like.*

Be careful of the circuit traces on the mylar and pay attention to the order the layers (3) go in. Rinse well in lukewarm water and air dry.

For fixed keyboards (laptops, in particular), turn the device off. Blow or vacuum the gunk from between the keys (I prefer vacuuming since it won't wedge crud in evil places). Dampen a cloth in rubbing alchol (use 81% alcohol as the rest leave too much deposit of their own)and daub the key tops. A general wipe off of the surrounding area and you are about as 'done' as you will ever get.

Please note, too, that an office toilet seat is probably being disinfected at least daily, if not frequently through the day, so the observation that keyboards simply have 'more' germs is pretty meaningless. Your FACE probably has more germs than that toilet seat, too. We live awash in germs. Get over it. Clean the keyboard when it gets too grungy and wash your hands before you eat, sterilize your mouth before you kiss and you'll be fine.
-- Bill

* Great for tormenting the H&P typists in your life.