Cleaning on can have different meanings depending on the context in which it is used. One possible antonym for cleaning on could be "neglecting", meaning to ignore or fail to give proper attention or care to something. Another antonym could be "contaminating", meaning to make something impure or dirty. A third antonym might be "cluttering", which means to fill or cover a space with unnecessary or disorderly items, making it difficult or impossible to clean. Whatever the antonym used, it will help to convey the opposite meaning of cleaning on, giving a more complete picture of the various ways in which tasks can be approached.