It is the question of the Taz why on Purim the emphasis is on mishteh vesimdha whereas Chanukah lehodos ulehalel? He explains, that on Purim, Haman wanted to destroy their body but Chanukah, the yevonim wanted to destroy their soul. It says in Pirkei Avos, wild animal comes to the world for swearing falsely. Asks the Binah Leitim, why it says comes to the world? He answers that the person not speaking properly, himself, turns into a wild animal, so it is important for us on Chanukah to cleanse ourselves spiritually by cleansing our mouths.