My experience of reading it definitely helped remove some aspects of the cult programming that I didn't even know were there to begin with. Having been born-in, there were some aspects of how people relate to each other that I just didn't know the cult wasn't normal. In the long-run, though, I've found it's definitely helpful to talk stuff through with a good friend or a therapist periodically - I may have an intellectual understanding of how I was controlled, but getting rid of those automatic responses takes continued effort.
It'll probably be different for everyone, but the hardest thing for me hasn't been understanding the way the cult indoctrinates and controls people and how not to allow it in my life anymore, but it's been unlearning all the defenses that I built up in the cult that are now purely impediments to me (even though they were a matter of survival when I was in the cult). One of the things I learned in the cult was that if something in your life is good, you don't share it with anyone or tell anyone about it lest it be taken away to make more time for cult activities. I'm still instinctively really guarded in conversation with people, especially if the conversation turns to something like my dating life or whatever. It takes a lot of reinforcement to shed those sorts of defenses.
Good luck to you on your journey! Keep making progress - as has been said many times: living well is the best revenge!