Dream Buster.
You can't eliminate the risk all you can do is to minimize to a practical extent. Some of the ideas of dicking arround with oils in the short term of your career span will likely decrease the reliability of the engine causing more Inflight shutdowns than you would care to experience. Yes there are problematic installations that frankly stink so crutching along with hit or miss maintenance seems like a reasonable degree of correction vs the percieved risk.
The government does not decide in-servce risk levels based on cost, it adresses them mostly on a prioritized basis of need. However, in this problem area very little hard statistical risk data is agreed.