The word "cruds up" is not commonly used in the English language and therefore antonyms for this term are not listed in any standard dictionaries. However, based on the possible meaning of the term, antonyms could include phrases such as "tidies up," "cleans," or "purifies." These words would indicate the opposite of "cruds up" - that is, to make something clean, neat, or in order rather than making it dirty or disorganized. In summary, specific antonyms for "cruds up" may not exist, but there are several phrases that indicate the opposite action.