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