One synonym for the phrase "make a clean sweep" is to "start fresh." This means to wipe the slate clean and begin anew without any baggage or issues from the past. Another synonym is to "purge," which suggests eliminating anything that is unwanted or not necessary. "Clear out" is another option, which implies getting rid of clutter or excess items. "Clean house" or "tidy up" are also common synonyms for this phrase, and both suggest cleaning and organizing the environment or situation at hand. Overall, these synonyms all convey the idea of starting over and eliminating anything that is hindering progress or success.