I try to keep a coil of floss stashed in the wallet for that urgently annoying morsel that occasionally shows up.
Sometimes I lose it or fail to replace it. It bothers the devil out of me to have something stuck in one of the front areas and exerting unusual pressure, so I have used all manner of inappropriate items as "floss".
The thing I discovered that is almost always around and fairly successful is a plain old plastic bag. Something similar to the type of plastic that a loaf of bread comes in. (cheap bread, not the artisan stuff in the crinkly wrapper) Just grab the edge an inch or two apart and it seems to do the trick.
Disposable shopping bag type of plastic is not as good. The bread type plastic is just a bit thicker and has a bit of "stretch" that helps out.
I also had an annoying situation one time that compelled me to carve a toothpick out of a credit card. That worked pretty good, too.