Misterlou,
I think that is a bit harsh. Paulo hasn't really described his situation in any detail; probably because it wasn't relevant to his question, which was about how to communiate with another aircraft.
However lets imagine that Paulo was doing circuits, in a C150. Another faster aircraft, lets say an SR22 (just because I like 'em), joined the circuit. Paulo turns downwind, and the SR22 joining crosswind, slots in behing him. Now the SR22 is maybe 10 feet above Paulo. Now if the SR22 pilot has Paulo in sight he'll slow down, or over take, and everyone is safe. On the other hand, if the SR22 pilot hasn't seen Paulo, he'll be catching the C150 very quickly indeed, and probably try to correct his altitude difference, and an mid air is imminent. Given that the SR22 is above the C150, and close behind, the C150 will likely be hidden behind the nose of the SR22 (unless the pilot has already seen it and taken corrective action). Given that Paulo in front and is flying a high wing a/c, he is unlikely to be able to see anything behind and above him.
Now your advise is for Paulo to rock his wings, and continue on, and when the mid air collision happens, for him to point his finger at the SR22 pilot, and say "I had right of way!"????
I can certainly see why a pilot in those circumstances would want to know if the other aircraft had him in sight, irrespective of who was in the right or wrong. It's not one to leave the insurance companies sort out!!
If I've interperated your post as being harsher than you had intended, then please forgive me. But as I read it, it sounded very critical.
For what it's worth, I think something like this might be appropriate in those circumstances. "zzz Information, Gxx is just in front of Gyy, and 10 feet below, at 80kt". It gets the info to the other aircraft very quickly, without be discurtious to the ATC.
dp