Contras' rhymes with:
contras, contras, contras, artra's, astra's, chitra's, cleopatra's, contras, extras, matra's, orchestra's, orchestras, petras, pietras, sinatra's, spectra's, ultra's
Contras' sounds like:
cantor's, cantors, cassandras, cemeteries, centaur's, centaurs, center's, centerre's, centers, centers', centres, centrex, centuries, century's, chandrika, chandross, cinders, cindric, comandeers, commander's, commanders, commentaries, commentator's, commentators, commenters, commodore's, commuters, comtrex, condors, condracky, condracky's, contours, contras, contreras, counters, countersue, countries, countries', country's