If I have an addict that stays around me and I want to help him, i will first attack his mentality towards and about gambling.
There are obvious stories about gambling that he might not have heard about, I will even create negative imaginations about the downsides of gambling and next will be to engage him as a form of distraction from the regular gambling activities.
A calmer approach is what is needed to create a solution for the addict to go out of his dilemma and not to cause more problem by attacking his mentality. I guess by attacking his mentality you probably meant to tell him negative stories but I bet you such addict have perhaps heard such stories and doesn't have the capacity to stop themselves. Therefore, it goes beyond telling stories but a action, a suiting action that he won't know you are working to take him out and before you know it he is already out of addiction.
No addict wants you to use force on them and if you try and fail, you would probably not get the opportunity to try again because they will keep some distance away from you and try to avoid you, including seeing you as an enemy that is trying to deprive them of their winning as they feel any time they try, they are close to winning which is why they hardly give up by themselves.
I agree with you, but let me also point out that, it is very important for a gambler who is addicted to say that he or she needs help, before we decide to extent a helping hand to such a person, going out of the street, and then seeing someone who is addicted to gambling, and throwing ourselves at him or her, in a bid to help that gambler may not always end well.
The only time I think we can offer such unsolicited help is when the person we are trying or wanting to help is a family member who is in close commission with us, or a best or very close friend or ours.
I say this because, some people are addicted to gambling and still enjoy playing it, most especially, those who are working or doing business and making just as good as enough money for themselves, and aside from being addicted to gambling, to them, gambling is also a way they ease off stress of that day after their activities at work or business place.
So, to want to advice such person to leave gambling either by force or by mild, when they did not ask for such help, could be you making yourself their enemy.