You're doing your best. You pushed, he pushed back.
The idea of going to therapy and CHANGING, even though it might be for the better, can be pretty scary. It's a leap off into an abyss, to an unknown destination.
That said, if he actually does go see a hypnotherapist (I presume about his smoking), that's a step in the right direction. I've been through hypnotherapy, my main therapist uses hypnosis with me, and believe me, even if he's in that room specifically to work on his smoking, other stuff is going to come up. The real question will be whether he goes back for the next appointment after the swamp in his psyche gets stirred up.
My bf smokes, and is an active alcoholic. He has tried to stop drinking. He did stop for about three weeks during the five years I've known him. But the reason he drinks is his ptsd symptoms. I can't see him really quitting unless he addresses the underlying issues. He's also been trying to switch from cigarettes to e cigarettes. Even that is really tough.
I've gotten a HUGE amount of pushback when I've suggested therapy to my bf. You're not the only one. But yes, I suspect you've planted a seed.
I'm not sure what factors move a person from denial of their issues and rejection of the idea of healing to a place where they are willing to take the risk of change. I have some ideas. But I hope your friend finds that path.