I've never indulged myself but after being around many, many cluster people I've heard a range of comments....it doesn't help and it doesn't hurt being far and away the most common. I've also heard a few swear it helps....and a few swear it's a trigger. Damifino.
I do know when I was a tobacco user even the thought of lighting up during an attack would make me worse....but then the first thing I wanted after the pain was gone was a smoke.