Incest rhymes with:
accessed, unprocessed, accessed, alkahest, altfest, armrest, backrest, bucharest, budapest, canwest, dataquest, envirotest, fieldcrest, finevest, fininvest, goldcrest, grundfest, hardpressed, headrest, healthvest, holmquest, inquest, manifest, marquest, megaquest, outguessed, protest, ridgecrest, sealtest, seaquest, silvercrest, skywest, slugfest, unprocessed
Incest sounds like:
immunized, incata, inched, incised, incite, incited, inequity, inexact, ingest, ingested, ingot, iniquity, inject, injected, inkatha, inkjet, inquest, insect, inset, inside, insight, insist, insisted, instead, institut, institute, instituted, instituto