Will it work as well as a dedicated CPU cooler at the same cost? Probably not.
Is it a good idea? Probably not.
There was going to be two loops in the keg the short loop is for the video cards and the long loop would be for the cpu. I was thinking of also using the mineral also in the loops. I do not want to have to keep adding water if I was to use it. I would use between 3 and 4 pumps for good oil flow. The only cost to me would be oil, and copper. Would the use of oil cause any damage if used in this way for a long period of time?