This is gonna sound crazy, but i've got something that works well if you're in a fix for some sort of skin lubricant...

Astroglide!

I'm pretty sure any type of "personal lubricant" would work, especially because they aren't petroleum based like a lot of lotions (petroleum based things break down latex in comdoms, and will do the same thing to your chamois over time). It stays on forever, and it's slippery as, well, astroglide...

Edit- I've found that astroglide stays slippry longer than KY in "non-bike" situations, so I'm guessing that it would carry over to cycling use as well