Time to let out my innner English Fascist. Yeah, sure, I'm a programmer now, but I have a degree in English Lit, and I spent three years teaching English in the public schools in Japan. I may have an unhealthy obsession with English minutiae, but at least I come by it honestly.
I'm still amazed by the number of times I hear people in meetings saying 'flush out' when they really mean 'flesh out.' In these meetings, the people are referring to some sort of rough idea or plan, where they need more details before they can begin taking action.
'Flush out' -- in a general context -- means to remove something undesirable from an enclosed space using a stream of water (e.g., flush out a clogged pipe). In the context of hunting, 'flush out' means to scare the quarry out of whatever place it's hiding so you can shoot or pursue it.
In the case of a vague or nebulous plan, the correct phrase is 'flesh out' -- i.e., the rough plan is just a skeleton that needs actual 'flesh' on it before you can take action.