Talcum rhymes with:
balcom, balkcom, halcomb, malcolm, malcom, malcomb, balcom, balkcom, bolcom, halcomb, holcomb, holcombe, malcolm, malcom, malcomb, unwelcome, welcome
Talcum sounds like:
talisman, talkin, talkin', tallahassean, talsma, telecom, telekom, telxon, theologian, tilghman, tillison, tillson, tilson, toalson, tolleson, tollison, tolsma, tolson