Quash rhymes with:
wasch, b'gosh, bosch, brosch, dosch, frosch, gosch, grosch, hosch, kosch, lawshe, losch, milosh, mosh, natchitoches, posch, prosch, radosh, rosch, rosh, tosch, wasch
Quash sounds like:
q, q's, q., q.'s, q.s, qawi, qi, qiao, qu, qua, quach, quack, quacks, quai, quake, quake's, quakes, quasi, quassia, quay, quaye, que, queasy, queau, quechee, quek, ques, queue, queues, qui, quiche, quick, quickie, quigg, quik, quiz, quizzes, quo