Chastising rhymes with:
advising, arising, comprising, decriminalizing, despising, devising, disguising, oversizing, revising, rising, sensationalizing, sizing, surprising, unsurprising, uprising, upsizing
Chastising sounds like:
catacosinos, catacosinos's, catching, catchings, catkins, cautiousness, chautauquans, chudzinski, citizen's, citizens, citizens', cutchins, cutesiness