I have to say I find some of the other items that last seemingly forever more disturbing than the Vaseline. Isn't that stuff just refined petroleum? Looks like it:
http://en.wikipedia.org/wiki/Petroleum_jellyInterestingly that wiki has some good information on when not to use petroleum jelly for certain things.
Anyway, it'll probably last forever.
Thanks again NIM for some really great advice. I find your advice more useful than a lot of other advice because you've given it such thorough personal testing prior to sharing.