I'm aware molly tends to refer to MDMA. But you can't get high from smoking mdma. Heat destroys it.
Around here (Florida) "molly" is typically a white powder that people either smoke out of a bubble(leaving the bubble black AF) or they roll it up with tobacco, sometimes weed in a blunt. Or maybe pinch out the end of a cigarette and replace with tobacco with the powder.
I accidentally tried some several years ago as it was mixed with weed so I thought it was just a weed blunt. The taste is fucking awful, though. I exclaimed this weed tastes like shit... Then the guy says, "yea, i put some hard on it." I never heard of that in this context (people don't smoke mdma.) And after further discussion he also called it molly and flokka(as have many others). And yea, people basically smoking Chinese bath salts along with random other shit. There's no single formula. The Florida State Police have released test reports that have included fent, pcp, bath salts, crack, formaldehyde, other Chinese-sourced industrial chemicals, rat poison, plastic, dry wall, etc... nasty shit.
Then again there are people that insist it's genuine MDMA and insist you can get high from smoking MDMA. But they're smoking random bullshit, so obviously not very bright. Huge red flag. People that smoke that shit ain't right in the head.