As he is a NRL player, banning him from playing NRL is the most direct way to show him that what he does wrong will have an impact on being able to do his role that I presume he wants to do.
Education would be a great 'additional idea' but that alone might not create a more direct 'cause and punishment' link for him.
He does seem to be too impulsive and lacks the ability to think first quite a lot though. Didn't he have that dig at a load of Roosters last year while at the Panthers - not thinking on that he was going to be working alongside them a few months later...