In the scene from Das Finale where the Anglerfish crew confront Ogin's crew in the bar, Yukari pulled out one of those stick grenades, and I wondered a couple of things. Is that a live grenade, and what does she intend to do with it?

Given Japanese weapons laws, the most likely (and simplest) answer would be that the grenade is a dummy or prop, and she would use it as a club. If somehow it were a live grenade, it would be a bad idea to detonate it in a confined space, so it might be a better choice to again use it as a club. Or she could do one of those "Return of the Jedi" style "threaten to blow up everybody in the room if you don't do what I want" gambits.