extruder and heat barrier found at walmart! cheap!

i have found out a way to make a heater barrier out of high temp cork found in the hobby isle at walmart stores and at home depot hardware section.

video of it working here
http://www.youtube.com/watch?v=TZ994gv_HaA
and it running at 285C here
http://www.youtube.com/watch?v=aHnd-BPtAmw