There are different approaches. I did it right after the worst fight we ever had, when we both knew we were unable to help ourselves, and I just quietly said, "There's a marital retreat I've heard about that's supposed to help people like us. I think we should go." And he agreed, so I booked it. Others have had a lot more trouble getting agreement. Pointing out that the children deserve for their parents to really make an effort to keep the family together is a good reason. Some people make it part of a bargain -- you do this thing that I want, and I'll do something else that you want. Sometimes asking the partner to do it for you, so you can have closure, or so you can feel that you two have tried everything, works. And since the workshop focuses on communication, not marriage counseling, many people just suggest going to improve communication, whether you continue on the path to divorce or not.
Retrouvaille usually discourages couples with one spouse in an active affair from coming. This is not a hard and fast rule. But their space is limited, and they know that couples with no outside partners have a better chance of reconciling. The only thing they ask of both partners is that you come "with an open mind and a willing heart."
