Don’t be intimidated by the ominous black bristles. This charcoal toothbrush ($6 at Schoolhouse Electric & Supply Co., 27 Vestry St., nr. Hudson St.; 212-226-6113) packs a purifying punch thanks to a brush head infused with Binchotan powder, a Japanese charcoal that dates back to the Edo period. The stiff nylon bristles scrub away plaque, karate-chop bad breath, prevent bacteria from reproducing on the brush in between uses, and naturally deodorize, should you ever find yourself suddenly out of toothpaste. Charcoal isn’t the only oral-hygiene innovation gifted to us by the Japanese. The Topland Etiquette Checker, a pocket-size breath analyzer, also has serious face-saving potential.