I've used CBT. A good therapist will help you set up the "program" and teach you what to do. Besides the sessions with the therapist there's usually daily "homework." I've only used CBT on a child with OCD so I'm not entirely sure how things will be set up for your husband. There are some helpful books on it. There's OCD workbooks and Jeffrey Schwartz's famous book called "Brain Lock." It explains and has photos of some of the MRI studies that show the brain before and after CBT (how the OCD brain becomes more "normal" after CBT). There's other books too that are very good. Most of mine are pediatric. I think CBT is wonderful.
There is no arriving, ever. It is all a continual becoming.