Cleanest rhymes with:
leanest, keenest, kienast, leanest, machinist, meanest, abolitionist, accompanist, antagonist, arsonist, botanist, calvinist, cartoonist, chauvinist, columnist, communist, conservationist, contortionist, determinist, dishonest, ernest, exhibitionist, expressionist, feminist, finest, gymnast, harnessed, honest, illusionist, impressionist, isolationist, jansenist, keenest, kienast, leanest, machinist, meanest, menaced, modernist, neoplatonist, obstructionist, organist, perfectionist, pianist, platonist, protagonist, soonest, sternest, unionist, violinist, witnessed
Cleanest sounds like:
calmest, challenged, cleansed, clenched, climaxed, clinched, collingwood, colonist, colonized, columnist