You can get a device from coolermaster thats totally enclosed for cooling your CPU and you don't have to empty this.
As for the distilled water, the second it touches your hardware its no longer distilled so the conductivity goes right back up again.
I did once try a PC in a disused chest freezer. Ie i filled it with water and added some pumps. I set the componants in wierd half plastic half metal material my chemist girlfriend made for me. And them immersed the lot in another liquid she made for me. Covered the thing with heat sensors. It worked too, sort off, intermittently.
Uni's great, they'll let you do anything they don't know about...