I have done this before and have a system set up for doing it, I was looking for for circuit tracers that people recommend.
Lake,
I saw one I want, in ECM, Racketeers, maybe $40.
It is a Sonalert mounted on a 3 prong plug.
(also includes a 3 light circuit testor).
(1) Plug it into 120V receptical,
(2) turn up the whistle volume to screeching loud,
(3) flip circuit breakers off (for a second only),
(4) listen for the whistle to stop.
Extech makes a whistle unit, which may work.
Amprobe makes several Open/Closed Circuit tracers at $400 up. Very Nice units.
Frequently I use a datacomm toner and banana.
I like the warble, but the circuit must be dead.
This is great for finding where a dead circuit terminates.
I have several houses to trouble shoot (behind another electrician)
where the Panel branch circuits do not get all the way to some parts of the house.
So, I have to trace them from the far (dead) end back towards the panel.
Since I always work alone,
always make a map and drawing (Acad),
this whistle device could be very handy, and cheap enough.