I think you identified the departments that are already doing it better than others. Even if no one is doing it very well, some departments will be doing it better than others, and you can use them as demonstration cases for how a healthy culture of disclosure can be created.
My impression is that you'll find it in the departments rather than through the Integrity Commissioner's office, because of the track record of how difficult it's been and how poorly designed the system has been, frankly.