I have also been re-lubing mine with lithium grease because Krytox was ridiculously expensive, but it doesn't last very long at all—at least in Florida. I opened it recently on our last roadtrip in the mountains where it was cool and I got a worse sound, so...I'm going to pony up and by Krytox when the weather improves. (EDIT: I just did, especially because I've accidentally hit the button before and it wasn't good) You don't use much, but it was way cheaper to buy an entire tub of it than a tube of Krytox.
The last I saw of this issue only one person said, "just buy the Krytox." Now everyone says it and for good reason.
There's a TSB out somewhere talking about what you need to lube exactly. I found it on this forum originally.