When i first started out with straights i bought some specific razor oil from The Invisible Edge, and a couple of razors that i have that are not in regular rotation are coated with it and it does a good job, no rust spots or anything like that, and a little goes a very long way. Would i buy more though? No, i think you could use pretty much any oil, i'd probably just use whatever was at hand in the future, and i suspect that Vaseline would work as well, it would be slightly harder to get into the pivot though, oil just sort of naturally migrates there with a little assistance from gravity.