A complete list of words acceptable in Scrabble with O as the second letter and O as the fifth letter runs as follows:

bolero, bonito, bonobo, booboo, boocoo, boohoo, bookoo, cogito, colugo, comedo, comodo, concho, coocoo, corozo, domino, doodoo, doppio, dorado, foredo, forego, forhoo, gombro, gomuto, gongyo, gooroo, gorgio, holloo, honcho, hoodoo, hoopoo, hooroo, journo, kokako, koodoo, korero, kousso, lobolo, loligo, modulo, mokoro, monoao, mooloo, morpho, nonego, nostro, pomato, pomelo, poncho, potato, roadeo, robalo, rococo, romano, rotolo, solano, solito, sorgho, toledo, tomato, torero, vomito, voodoo, vorago, vostro, zocalo, zoozoo, zorino