Yep. Got to fiddle around with Fluorinert cooling years ago.
Interesting, just not very practical.
You really DO need a fully sealed system and ostensibly clean-room assembly. Because, while the coolant itself is non-conductive, any detritus that accumulates in the fluid after settling out of the environment ISN'T. That's the main thing about water (straight H2O) isn't conductive. It's all the other things in the water, minerals, dust, etc that's doing the conduction.
Also, as noted, there's STILL going to be use of fans and water. Because you still need systems that extract the thermal energy from the liquid medium. You simply remove them from the main system chassis.
It also doesn't change the fact that it's still a TERRIBLY inefficient way to cool the system. Unlike water cooling loops, where you have no more than maybe a pint or so of fluid cooling the major heat sources in the system, you have QUARTS of fluid basically covering everything. And you really have no good flow control, other than extremely high volume fluid exchange, which is energy inefficient in and of itself.
That's PROBABLY what a lot of the board re-engineering is about. Centralizing all the thermally active devices into a centralized area to limit the volume of immersion coolant required and to simplify flow control.