The administrative law judge may arrange for the services of a qualified mediator to work with the parties and attempt to bring about a settlement. The administrative law judge may assess costs of the mediator's services against the parties in the same manner as other costs or may require advance payment. The mediation ends when successful or when a party decides that such party no longer wishes to participate in the mediation. The parties shall immediately inform the administrative law judge when the mediation ends. An offer to compromise or a statement made during mediation may not be admitted into evidence or considered for any purpose in the hearing of a case in which mediation was attempted.