I’m not making this up. You can buy zipper lubricant in a can. And it’s called Jig-A-Loo:
The manufacturer calls it a “lubri-pellant” and recommends it for zippers and practically everything else you can think of. They claim it’s non-staining. This would make it appropriate for luggage…or trousers. And, hey, it’s from Canada, eh?
From the website FAQ:
Yes, Jig-A-Loo does not stain. Have a stuck zipper on your white jeans, your wife’s dress? Your kid’s jacket? Or another piece of clothing? Just spray it with Jig-A-Loo for quick and clean results.