I did a quick search for mineral oil and did not see anything immediately, so sorry if I missed it and this was posted before, but this is really cool and I want to do it. I just may with my upcoming upgrade.
http://www.pugetsystems.com/submerged.php
I have a couple questions though. They say on that site they do not recommend OCing with this as temperatures above 75C has a risk of tank failure. Why would that be? Also, I think I read from a few different sources that an i5-3570k OCed in the 4.3 range only reaches temps of 65C, which would lead me to believe under this system of cooling it would be ok. Even if the chip reached those temps the Oil certainly would not.
What do you guys think?