I just had a paid open ai service tell me all about a command line argument that doesn't exist.

It isn't possible to do what I wanted with the proposed command, but the hallucination helped me to Google a method that worked.

What do you mean? Hallucinations are unavoidable, even humans produce them semi-regularly. Our memories are not nearly reliable enough to prevent it.

In my experience the only more or less reliable way to avoid hallucinations is to provide the right amount of quality information in the prompt and make sure the LLM uses that.