It has been mentioned that mineral oil and vegetable or similar (glycol) oils may not mix. It's possible not enough olive oil remains to make a difference, but miscibility can be easily tested. Hydraulic fluid has been mentioned. That comes in both versions. DOT 3, 4, and 5 are glycol based.
I got 2 weeks from a bad mother board fan when I used whatever sandwich oil they had at the little sandwich place nearby. and IIRC then it jammed up, instead of just spinning loud. So it got quiet instead of screech after the oil and then 2 weeks later it was quiet because it halted. then I played games in tiny windowed mode on low res without the fan for another month before I got scared and replaced it
it dries up gummy like a cast iron pan I think and really gunks it up.
BTW WD40 is the oil you use for its original purpose, water displacement. after you wash something, rinse it in alcohol, drench it in WD40, let that drip off and expire, then add a viscous oil. I think the WD40 actually DOES get rid of some water in like a pliers hinge. It's like a rinse
I thought that basically they used it for this: hosing down pressurized thin stainless steel tanks used for liquid oxygen for rockets. I imagine those tanks might get some dew on them in the morning, so you have someone spray it down with the oil on a humid day to get rid of the water droplets. Solvent evaporates too cold and makes more condensation, I have seen this on PCB. Thats why you bake PCB after flux remover with alcohol or whatever in a can. So it can't evaporate too fast, it can't absorb the pressurized thing that might make it evaporate and cool down, and it can't absorb water like solvents would (hydroscopic) and it must wick very well to get into small cracks and stuff where water can accumulate and start rust corrosion, and it needs to be cheap if its actually a water remover, which is why I think it was so hard to get WD40 working right if the story is true at all. And it has to evaporate quick enough to allow you to add a proper sealing oil to the surface.
But even if you have a nicely sealed tank, if you see dew on it, the smart thing would be to rinse it off... they could not just assume that a egg shell LOX tank would be OK because it was greasy when it had condensation on it.... that is a flaming disaster waiting to happen... I assume they tended this thing like Emperor Vitellius' stomach LOL