Yes, oil does go rancid, and it is hard to recover from that. Olive oil does not polymerize the way that walnut oil or linseed oil does. And, the bacteria attack it because they do not attack the mineral oil. This resultantly makes it a very bad choice for any wood finishes.If we have already used it, we need to wash the surface with solvent-like mineral spirits. And then, let it sit for a while, just wipe it off, and repeat until the olive oil is gone. Then, we can replace it with more suitable oil.