It is, if you look back you will see lots of OC results and discussion of cooling
here is my ln2 toys and other cooling stuff ;)
CPU pot by Duniek
Sub zero prep on my Foxconn BlackOps
In the middle of prepping my DFI UT X58
Test run to check my water
cooling out before moving up to the slush bucket setup.

CPU LN2 pot designs by me.

30L LN2 dewar ($50 on ebay)