Bluntest rhymes with:
advantest, apprenticed, dentist, faintest, orthodontist, advantest, anabaptist, anesthetist, apprenticed, artist, baptist, brightest, cornettist, cultist, dentist, faintest, fastest, fattest, fittest, greatest, hottest, lastest, latest, librettist, lightest, neatest, noticed, orthodontist, practiced, quietest, quietist, remotest, slightest, smartest, softest, strictest, sweetest, swiftest, tightest, wettest
Bluntest sounds like:
blindside, blindsided, blondest