I think it is a bad idea. If you must, then send him a short letter. But do not see him personally, and don't get on the phone with him. Make sure what you say is final, that there is not a space for him to comment.
I agree with Deauxlie. Nothing speaks louder than silence. You have told him already you are working on your marriage. Silence says that nothing has changed, you are working on your marriage.
It is so easy to snatch defeat out of the jaws of victory. I've done it so many times myself. Not all relating to love. I'd say professionally, I have gotten in my own way a lot.
