That was insane...Wow.
Very very old. Here's the original article : http://tomshardware.co.uk/2003/12/30/5_ghz_project/
Didn't some guys put a computer (motherboard with components) in some special liquid and used liquid nitrogen to cool the liquid.
I think you're talking about the mineral oil project. It's non-conductive, so you can dunk the whole motherboard in it.
Technically water is non-conductive, in a pure state.
More reliable and less hassle than constantly refilling your nitrogen reserve