In her blog about neuroscience and ADR, Stephanie West Allen, writes about research finding that individuals displayed lower stress after affirming personal values prior to a stressful situation. Allen notes that, "Although doing a values exercise is probably not going to be appropriate in many conflict resolution settings, getting disputants to recall important values is often done either deliberately or instinctively by those skilled at conflict resolution." (Brains on Purpose.)
I know of one transformative mediator and business consultant, who might embrace this approach. Sean Mason has his clients undertake a "Core Values Exercise" as part of the dispute resolution process and is writing a book about the methodology. Even if such a direct approach might not work for every onbuds, it may be valuable to include a discussion of values with new visitors.