Yeah that is another option for working fluid. IIRC they used Novec 649 (boiling point of 50C).
Quote
I've been researching this product and is a different family of 7000, this is a acetone that can break down the coating of the wires, we are studying other solution is to use the Novec 7100 has a voiling point to 61º and mix it with the 7000 to reduce it, this tells 3M is possible.
Who told you that Novec 649 is acetone? It is Fluoroketone, tested to be inert enough for such purpose.
Also I have official 3M response that Novec 649 is recomended fluid for immersive cooling.
You can check here
http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=4509386&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel5%2F4476516%2F4509347%2F04509386.pdf%3Farnumber%3D4509386
http://solutions.3mdeutschland.de/wps/portal/3M/de_DE/Novec/Home/Product_Information/Products/?PC_Z7_RJH9U5230OLLB0I4HB8HRT3OC0000000_nid=F55Z1XTKWXbeQQBXSJ1LVVgl