I know your question is very tongue in cheek
however, I get a bit anal about oil, so you've started me off now!
During my merchant navy days we had lub oil and hydraulic oil absolutely everywhere and it used to amaze me how much water you could build up in a header tank that had no exposure to water systems or the elements. The answer was, of course, that lub oil and hydraulic oil in particular is very hygroscopic, in other words, it loves to absorb water vapour then condense it into water droplets, and water in hydraulic oil is not good! Causes wear, corrosion, sludging, foaming, gassing and general oil related mayhem and skulduggery not to mention discolouration. Consequently, I wouldn't leave high duty oil, (like hydraulic oil) in a system unless it was sealed (AC etc) for more than 3 years tops.
The first job I did with the Flying Machine was change all the oils including steering and AC and some like the brakes and steering I did twice for good measure. Consequently, the FM drives like new.
I don't know how long yours has been in the car, but I think your idea is a very good one from the look of things, and I'd change it again after a short interval, personally.