No, not a good idea. I was part of a forum where men were encouraging each other to stop their porn addiction. One day, a new member posts: “Hey! What’s wrong with you guys? I love porn!” It’s like walking into an Alcoholics Anonymous meeting and telling everyone there that booze is great. Really?
I would go to general, non-porn, discussion forums that allow postings, or advertising, like: “Addicted to porn? Let us help you stop.” Then put in a link. Porn addiction is common. Lurkers, if not members, would click on this.