I don't have a video.
Gigantea tentacles can vibrate. They don't always, and sometimes only some of the tentacles vibrate while other tentacles don't. Vibrate is not a good description of the movement. I would describe it as "wiggle" or "writhe". They move back and forth in a somewhat wiggly serpentine fashion. In my experience they are more likely to do it when there is little / no water movement.
By the way, S. haddonis can also wiggle their tentacles in a similar fashion, but in my experience don't do so as frequently.