It is a self-screening process. If you think you can benefit from Retrouvaille, then you should go. They send a confirmation letter to the couple in advance asking you to attend with an open mind and a willing heart. Some people balk at that statement and fear going. I wondered myself if I belonged there. In fact, my mind and heart opened while I was there. In some places they ask both spouses to sign the letter. We didn't have to do that. They also tell you in the letter that you should have no active affairs or drug addictions. That is the selection process.
Most people think Retrouvaille is like counseling. It isn't. It is a private weekend for the couple with no group discussions. There are no therapists. There are presentations by 3 couples who tell their personal struggles, reconciliation and healing. Then they teach you the dialogue discussion technique and you practice it.
When people say it is intense, they are referring to the thought they put into writing about themselves. There is no pressure. You simply write about your own feelings and discuss them with your spouse. It is a very low pressure environment. There is time to wander the grounds and be alone, or to be with your spouse.
I have heard that story before of people leaving. But I don't know where it came from. No one left when I went, and I've asked people from other weekends if anyone walked out, and they said no.
Since they teach communication, the weekend can only help people. Whether or not you stay married, good communication is a plus. I've never heard anyone say, "the problem was we understood each other too well. So we couldn't get along."