Caporegime
Yeah because water is great on your gpu and motherboard.
You could easily have a solid block throughout the psu with the tube connections external.
Never said it was great but chances are it would only take out that component, water in the PSU however would likely blow your whole rig.
I just don't see how it would be required, just buy a PSU with great efficiency and rated well above the power draw required and it's never going to get hot or the fan spin up to levels any higher than fans on a radiator.