If you've got liquid in it, stop using it immediately.
You should only ever clean a keyboard with a slightly moistened lint-free cloth - there should be no liquid produced if you squeeze it.
If it's plain water, hang the keyboard in a warmish room with good air circulation and leave it for about a week to dry out.
If you've used chemicals or spray polish, you've probably lost the keyboard, but in that case you can always try the most drastic method as there's nothing to lose.
That is to remove all the keys (you can get a plastic tweezer tool for this) and flush the board under a running tap until all residues are removed. Then hang it up as before to dry out.
Clean the keys individually and don't replace them until you're sure the whole thing has dried.
I did that with a G5 keyboard after spilling most of a large glass of wine in it and thankfully it worked (and I had a spare keyboard to use in the meantime).
It is, however an extremely tedious job!
With current aluminium keyboards with low-profile keys, that drastic measure may not be possible.
If you need to replace the keyboard, be aware that the keyboards currently on sale in the Apple Store will not work with full functionality on any OS earlier than 10.6.8.