Here's what rhymes with diphthero.
no so know go though low show ago co flow slow snow throw row tho fo foe ho lo bo doe dough fro mo po ro toe wo woe chateau hello thro tow yo beau ceux faut goe hoe jo ko sew soe uno vo beaux cho dau floe mow noe roe sho yeux zo chateaux rho stow throe sloe whoa doh schmo schmoe blow grow pro glow quo bestow crow bio aglow escrow tuo bro dunno trow chapeau kapok tarot turbot kayo chapeaux although below ratio overthrow plateau audio buffalo overflow folio indigo forego forgo nouveau propos tableau vertigo aliquot dicho siglo tableaux topos plateaux oleo piccolo deathblow foreknow overgrow gateau fatso gateaux pekoe borzoi resew radio studio undergo patio portico stereo bungalow calico dynamo polio apropos cameo domino mistletoe outgrow presidio rodeo spatio afterglow trousseau adagio pistachio undertow regrow bandeau matzoh pompano trousseaux romeo tallyho embryo politico medico oregano pianissimo mustachio moustachio portfolio impresario microdot braggadocio archipelago generalissimo