I used to be a 'hardened smoker', highly addicted. I didn't need revoltingly graphic adverts, because I disgusted myself on a daily basis.
I saw a lung diseased by cancer when I was about 14 - someone from the local health authority came to our school to give a talk about smoking. The diseased lung was shown alongside a third of a healthy lung and both samples were the same size. I'm not talking about pictures - I'm talking about actual lungs, preserved in formaldehyde in glass jars . We were all invited to take a close look. I'll never forget how disgusting the cancerous lung looked. But it didn't stop me from starting smoking within a few months.
So my experience says that shock tactics are a waste of time.
When I eventually gave up several years ago, I was surprised to find how easy it was. And I realised that the hardest part was actually making a firm decision to quit. Smokers always make excuses why they can't do it just yet - a holiday coming up, Christmas, a birthday, a party to go to. The truth is there is no 'right' time to do it. You just have to take the bull by the horns and do it.