> to go to the plumbing department of any hardware store and buy a tiny
> pot of "plumber's grease".

That's what I'm using, but mine is in a tube. Exercise some care that you don't have any sand, grit,or other stuff on the o-ring after you've greased it. It's easy to pick up a small crumb if you're doing it on the kitchen table (greasing your o-ring, I mean).