We made something like this some years ago. We submerged a MB in oil and put the whole thing in a freezer. It worked great, until the oil penetrated in between the pci card slots (yes, it was an old computer)and MB. This also affected the ram slots. This made the electrical connection between ramMB and pciMB pretty useless after a while, effectively shutting the thing down. We soldered the ram and pci cards to the motherboard, and this solved the problem.