I'm not sure vaseline or another oil is going to cut it at this point. The intent with those is to suffocate the mites, but those are some really badly infested feet, I think it would be too hard to get the vaseline up close to the mites. They're all under there, after all. Maybe once the old, crusty scales come off.
My suggestion would be Epsom salt soaks, then, after a soak, apply a mite treatment, then put Vaseline or similar over that. Cover all your bases.
My suggestion would be Epsom salt soaks, then, after a soak, apply a mite treatment, then put Vaseline or similar over that. Cover all your bases.