In this article (Laws of Koshering (Hag’alah and Libun)) you specifcally say “Glass, plastic, glazed china, glazed dishes, Corelle, Pyrex, Corningware, or glazed earthenware do not need any Koshering, since they do not retain any flavor.” with no difference noted between ashkenazim and sephardim.
Has the Rav’s opinion on this changed?