No, I didn't use such to put free money into the economy. Or at least I would only try to take as much as they had.what you describe, in your latter and refined version, is what Spoonwood (i think still under his old nickname) posted here quite a while ago.
i understand well how it works. i also understand that it was obviously already in use in HoF-games, and by the rules righteously so. i did play around with it a little myself.
but i also agree, that it nullifies the essence of the game. so i deliberately forgo this option, even if it arises "by itself", and i definitely do not especially look out for it.