this article on getting a computer system to work is a fascinating read and very informative. the whole washing the entire system thing is rather bizarre though. one comment talks about using isopropyl alcohol vs water (more expensive, but much safer). your moment of zen:
Silicon, aluminum, and gold don’t rust. They on the other hand conduct electricity as equally well as water does. I could probably write an article unto itself on how and how not to do this. You just can’t jump into it.
Once you have finished rinsing it off, get a good grip on the hardware, and shake the ever living hell out of it (within reason you don’t want to put so much force into it that something bows or breaks). Then I set it within vicinity of a space heater and let the warm air quickly dry off the remaining droplets.
Cleaning the motherboard this way is the most difficult. The battery must be removed. It must have had enough idle time unplugged from both the battery and power supply that any residual charge has bled off.
After rinsing it off, you will find that shaking it and putting it before the space heater is not enough. You will have to physically put your mouth on the part and suck the water out of PCI, ISA, AGP and other such connectors which have small porous surfaces. Spitting it out or swallowing it is your choice, it is just water after all. Then it gets placed back before the space heater and left for a number of hours.
This isn’t something you hurry through. It is also not for the faint hearted.