Last Friday, a sidewalk display gave Capitol Hill lunchers second thoughts about their salami-and-onion subs. On Pennsylvania Avenue, across from the Trover bookstore, dentist Richard A. Miller hawked his 58-page paperback Beating Bad Breath: Your Complete Guide to Preventing and Eliminating Halitosis (American Literary Press Inc.). Passers-by seemed understandably reluctant to linger at the bad-breath booth, and Miller himself seemed shy about discussing dragon breath with random pedestrians. But two publicists energetically distributed a neon-yellow “Halitosis Self-Diagnosis” packet including floss, gauze, and a little poem about oral hygiene. Interested parties were encouraged to take the test themselves or pass it along to a smelly co-worker. Miller is all for telling friends and loved ones about their exhalations; in fact, Breath‘s most entertaining chapter is devoted to breaking the news either anonymously or in person (“Suggestion: Gift wrap this book without a card and leave it on someone’s desk”). “[Halitosis] can ruin romances, and it’s also a big part of business success and failure,” says Miller, who estimates that a whopping “56-65 percent of the population has chronic bad breath.” Binaca users take note: Miller is skeptical about mouthwash, and spends most of Breath advocating the chemical toothpaste additive ClO (chlorine dioxide). Not a hint of halitosis emanates from the dentist, so he must be doing something right. All D.C., Maryland, and Virginia proceeds from Beating Bad Breath go to the mid-Atlantic chapter of the Make-A-Wish Foundation; the $8.95 volume is available at the Trover Shop or from Miller’s Alexandria office, (703) 931-4242.