If we both agreed all the time, one of us wouldn't need to be here.
My advice comes from personal observations about what offers the greatest likelihood of success, not guarantees. MCing when one of the spouses is actively involved in an affair RARELY "works," if you want to definite "works" as being the return of the wayward spouse to the marriage and, ultimately, reconciliation. If CBK and his wife can use it as a staging ground to discuss their family issues in a constructive and civilized way, there's certainly no harm in it, so long as the family's other financial needs are being met.