I work as a person-centred Counsellor with individuals and couples. This approach isn't really solution based. In solution based Counselling goals are set and the Counsellor has some control and direction in how the sessions are structured. The way that I use Counselling is to offer a place which is accepting and understanding to you both so you both feel able to explore your difficulties and talk openly to one another. You are in control of the sessions in terms of content and direction.
I do feel that I am able to offer support to couples in your position but I often recommend an initial session of Counselling where we can all meet and discuss this further to see if we are suitable to work together. There is no obligation to continue after this session but it can often help in your decision about whether I am the right Counsellor for you.
I don't think it's worth a pinch of salt. What good is paying some third person to be there as you & W talk to each other? You two don't need to be in "control", but rather have a professional who knows how to guide you.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!