At the end of the day I’d say go for whatever is doable, as having something will be better than having nothing but a good idea.
I imagine the Luke figure batting fire toward the walker would be the best bet for about a second of footage followed by laughter. If Luke vanished without reappearing it may seem like the children are laughing at the defeat of this traitorous Jedi figure.
Even so, there’s probably a better idea in one of our heads.