I smoked for about 13 years, tried giving up a couple of times and didn't manage - then read the book, and quit, never had one since, over 10 years now. Occasionally I whiff one in the summer sunshine or see someone smoking glamorously in a film and have a brief pang - for about a minute - then think of the phrase which goes something like, 'every one you have makes you want the next one more' and know that it's best to leave it. It very soon passes.
I realised it seemed like brain washing but i was choosing to be brainwashed to stop me behaving addictively IYSWIM. There's also some mild religious content and despite being a staunch atheist i just let it slide for the same reason.
I think the key is, you have to want to give up. If you really want it then I think this book will work for you. If you're not sure then have a big think about why that is - but it seems you are!
Don't expect instantly to feel healthier, I didn't and was disappointed - but DO expect to feel almost instantly free! Especially of things like - going to the cinema and wondering if you can enjoy the whole film without wishing you could have a cigarette, or coming home in the evening after a long day and then wondering if you need to go back out in the cold to the corner shop or will those 4 cigs last you the night?
WARNING - giving up smoking can seriously affect the rest of your life - I found once I had become a non-smoker, having thought I was a 'smoker', I was able to challenge loads of other preconceptions I had about myself and made some big life decisions (all positive) because of it.
Good luck, but you don't need luck - you just need to be glad about what you're doing and enjoy it!