Almost any switch mode power supply has one of these chokes for noise suppression. The type pictured below is the type that has been tested working.
The prewound choke Coil has even windings on both sides and uses many turns of thick wire around a ferrite core.
Using the standard Joule Thief configuration, it has been tested with a BD139 transistor, 1.4K Ohm Feedback Resistor and a Blue LED.
Starts up easily at 0.6V DC. and is much brighter than the standard joule thief at 1.5 Volts.