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