"Be daub" means to smear something with a sticky or greasy substance. The antonyms of this phrase could be clean, scrub, wash, or polish. If something needs to be free of dirt or stains, it must be cleaned thoroughly with soap and water. Similarly, scrubbing entails using an abrasive agent to remove dirt while washing involves cleaning with the aid of water. On the other hand, to polish means to make something shiny by rubbing it with a soft cloth or wax. Therefore, depending on the context, these antonyms of "be daub" can be used to convey the opposite meaning.