If you think of an Architecture Review with the same mindset as an IRS Audit then something is terribly, terribly wrong. Properly constructed, and properly managed, the Architecture Review Board ought to be the one place any project team would want to go for two specific reasons; to get the right, best answers to any question, and to have the confidence that a proposed solution is endorsed by the most experienced, trusted business-driven technologists the organization has to offer.
The board should be comprised of individuals who are the thought leaders for the architectural domains of the enterprise. That would typically include database, security, web hosting, information management, and what ever other domains your organization feels is key to driving business value. Who in your organization is the most accountable person relative to database designs / architecture (for example). It doesn't matter if that person is an executive, an analyst, or a manager - that person should be on the board ... and no one else who might represent a competing "Database" interest.
Once you have identified and assembled the list of individuals that represent the key architectural domains (every institution will be different), you then have to get them to articulate in written or diagrammatic form their architectural standards. Call these reference architectures, operating practices, standards, or guidelines - call them what you want, just make sure of two things. First, that they don't conflict with each other, and secondly, that they are published and easily accessible. The rules for which designs are preferred or acceptable versus those that are unacceptable shouldn't be known only to mystics, the enlightened, or off-worlders.
You now have the ingredients for an Architecture Review Board that is sought after rather than avoided. You now have the one and only venue in the organization where a project team can bring their proposed solution and have it vetted by the people who are the most trusted problem solvers in the company. Remember, that by publishing and advertising the aforementioned 'standards' you are likely to find that most of the proposed solutions already fit into your desired architectures.
As you conduct the meetings, you must find a balance between confronting issues and allowing confrontation. Respectful, professional behavior and integrity must rule the day. Do not confuse experience with intelligence - the teams bringing proposed solutions to the board may not have the years of experience achieved by the ARB members, but most of them will be smart, educated, and proud of their solutions. Always talk in terms of desired company practices rather than right or wrong.
Following these simple guidelines will enable any organization to build or reconstruct and ARB that provides value and impact.