Distilled water will not damage the electronics in the Keyboard. It will not harm the circuits, because it doesn't conduct electricity. It's the same with this modded PC, whose mainboard is under oil: http://modbros.de/03c19898dc0a4ae01/index.html And when it dries, there won't be any salts left on the PCB, because there are no ions in distilled water. So, electrically, you're on the safe side for sure. The thing I'm concerned about is, that iron parts might start to rust if it doesn't dry fast enough. I know nor which materials are in a SY99, neither how expensive such a keyboard is. Do this at your own risk.