Never done this myself but know some ppl who have done it....it's a two way debate I would say, water has more conductivity and evaporates and sometimes corrode ur cooling system...oil gives u a good flow at a very high temperature, but only if u use the right viscosity....u may have a chance of blocking the cooling system...cause the oil is not going to be hot all the time specially in a cold morning...the cooling system has a lot of tiny and narrow pathways that only water flows through so have a chance of blocking those with oil....I would rather suggest using a high quality radiator coolant instead of mixing a little oil....normally u don't have to change or refill radiator coolant in new cars for 6 months(sometimes much more) I have a 21 yr old engine and don't change the coolant for three months sometimes....as long as u take good care of the engine and cooling system...it should be ok with a radiator coolant unless u drive erratically and smash the sh*t out of the engine, u shouldn't be worried.....
I have a drift car as well for which I change the water pump, check water hoses and change the coolant everytime I go for a drift...for such purpose car I would never recommend the oil mixing method...
Fellow members might have different views to all this...