Gee,
You guys have it easy over there!
On this side of the black stump, every electrician that certifies work that entails RCD's (GFI's) is required to test every RCD protected circuit and record the trip time and current on your Certificate of Compliance.
The proper tester for this costs an arm and a leg and maybe some fingers too.
As a quick test though when fault-finding, I use a solenoid type voltage indicator that draws about 240mA when you press the solenoid button on it.
