Here's what rhymes with decoo.
coup qu ku coo cou gu goo to who you do two new too due knew du grew que u crew q shoe zu clue cue dew glue lieu queue shew su sue tu vous chew cu deux fu lu rue zoo bu hu ju jus loo mu nu peu pu seu shu sou vu woo yew yu beaucoup boo chou chu doo ewe feu ru shou thu tue vou wou wu clew moo pooh poo shoo gnu roux thew whew achoo into through few true view blue drew pursue threw blew flew screw anew canoe hue renew accrue ensue flue slew stew taboo adieu ado brew flu jusqu pew piu skew tattoo thru eschew fue hew mieux shrew tzu vue mew kazoo slue phew booboo bamboo undue debut undo outdo revue sprue vnto askew imbue outgrew redo strew halloo spew valuer bugaboo endue foreknew zebu peekaboo bestrew buckaroo prevue wazoo regrew atishoo review revenue residue withdrew avenue rendezvous retinue subdue untrue caribou overdue barbecue kangaroo shampoo sinew overdo ballyhoo cockatoo barbeque indue marabou muumuu overshoe superglue overgrew interview hitherto overview construe overthrew honeydew fondue overflew overdrew hullabaloo misconstrue