I know it won't work (it has never been tried) but a mediator, no matter where from, should take the approach of a marriage counselor. The dynamic is the same; these people have to live together. But if only one person goes to counseling or both go but one in bad faith, it will never work. It would be the same as disconnecting half the spark plugs on your car engine: it will run but it won't run right.
Israeli vehicle hit in drive-by shooting in West Bank; no casualties reported (Haaretz)