Wiping the keyboard daily to get rid of dust and grime is a good idea but washing is an even better idea. The silicone skin can be soaped, rinsed then wiped dry before replacing over the keyboard. It was Speedy who originally wanted one for his MacBook Pro but found the P1600 price tag a bit steep. The one that fits the aluminum keyboard of my iMac was at P800 at PowerMac (Trinoma) in black, blue, pink and clear. The brand is XSKN.
I’m now looking for the ultra clear full screen silicone protector for my iPhone.