Cool!! We'll have to try it!I use cat harnesses, as long as the ones I have fit right with the bird. For a leash I had some baling twine sitting around (I was looking for something that was extremely lightweight), and I just tied a clip on the end that I also had sitting around.
Some birds absolutely will not tolerate having a harness on. I'm sure if you gave them enough time, they would get over it, but I don't make mine wear them if they completely hate it.
Here is a pic from this evening of my 3 month olds.