Forgot to mention I do believe he needs to go "cold turkey". Because having "a little porn" in your life, if you have been consumed by it, is not an option...
It is an OW of its own. And we are amazed at spouses who think they can be friendly, socialize, work with their former affair partners and that "nothing will happen". The same can be said of an individual with a sexual compulsion/addiction. They can't have a casual relationship with that stuff.