[Vwdiesel] What is the candle wax GP extraction trick ?

[LBaird119 at aol.com]

  Kroil is the penetrant I've found to be quite impressive. 
  I wouldn't try pulling that glow plug with the head hot, comfortably 
warm but not hot.  The most common time that spark plugs pull the 
threads out with them, from an aluminum head is when they're kind of 
stuck and removed hot, in my experience and conversations.
    Loren