"If he is still spending time with OW, then in my opinion he's breaking the trust that both of you are going to go in with an open mind and a willingness to try to work things out."
In their case I think the willingness is only to learn to communicate. I think though that Retrouvaille has loosened up they don't even ask that anymore. All they ask for is the willingness to go through the weekend. And regarding OP's, they only asked that the OP not be contacted during the time that Retrouvaille is being conducted.
In my case, my H went in seemingly unwilling to work things out, but came out of it a changed person.
Miracles can happen, and for me , as long as the person is willing to go in there, I would say go for it.
Me:49 H:45 D:12 M:14 T:18 Bomb: 6/26/10 EA: 9/3/10, fizzled out slowly, now ??? 11/5/11 Retrouvaille Finally piecing.... Its peaceful at last, but we got a looong way to go