No that is NOT a proper or useful way to test 3-terminal regulators. The technique is valid for SOME (but not all) kinds of transistors. But it is completely unsuitable for an integrated circuit like a 3-terminal regulator. It will yield unpredictable (and most likely meaningless and misleading) results.
If you don't have a DC power supply, why do you even need to test 3-terminal regulators? For that matter why do you even need 3-terminal regulators at all? Absent the context it is not clear what you are trying to do here?
You can use batteries as a DC source. Remember that you typically need 3V HIGHER input voltage than the regulator puts out. It would also be prudent to put a LOAD on the output of the regulator. At least something around 500 to 1000 ohms or so.