Yes, mineral oil is excellent to use as it wont go off as quick as other oils do (you can use olive oil etc.. but the go rancid quickly). I've seen an article in a UK pc mag that shows a PC assembled in a plastic storage box and immersed in sunflower oil. The top is sealed bar the wires. You can then over clock the sucker. My mate and i used to use ice cubes in plastic bags...though it proved fatal for the poor Pentium 60 we were trying to overclock at the time
