Disclaimer The opinions expressed herein are my own personal opinions and do not represent my employer's view in anyway.
You either are ethical or you're not. So as Madison and Washington both craft "ethics reform bills", consider this thought. Instead of trying to craft a bill which attempts to force unethical people into behaving ethically (which is guaranteed to fail, and will only hide the problem behind layers of bureaucracy), why not craft a law which allows unethical people to behave like themselves, but drags that behavior out into the light through high levels of transparency so we can all see it, and then voted based on it.
After a few rounds of elections, ethics may not be a problem any more.