Here's what rhymes with hardcoal.
coal goal kohl whole role soul hole pole roll sole bowl fol mole poll toll parole knoll shoal dole droll foal bole boll thole troll vole tole prole dolour skoal stole scroll stroll cajole oriole rissole patrol enroll casserole extol vacuole arteriole petiole unroll bedroll condole maypole extoll control glycerol systole camisole cubbyhole beanpole innersole quadrupole buttonhole decontrol pigeonhole profiterole