Q: Is it correct to say, “I need to clean house” when what you really mean is “I need to clean THE house”?
A: The phrasal verb “clean house” is pretty well established in English. Like many verb phrases, it’s idiomatic, which means it may not look exactly right when parsed literally, though in fact it’s perfectly acceptable.
A couple of other “the”-less examples from housekeeping are “do laundry” and “cook dinner.” No article is needed.
The American Heritage Dictionary of the English Language (4th ed.) notes that the phrasal verb “clean house” also has a meaning in slang: “To eliminate or discard what is undesirable. The scandal forced the company to clean house.”