I used to do it with a pair of headphones as a teenager. There was (and still is, thinking about it) enough of a gap between my first and second premolars to fit a cord. It’s like the same appeal as a fidget cube, only not healthy.

edit: premolars not molars

Hey man, they are on to something 😂 it was usually headphone cables for me - back when headphones HAD cables that is ROFL