Product review (5 stars): It works!
It's a syringe with a length of plastic tubing attached.  I suppose I could made my own and saved a couple of bucks, but the convenience of just ordering one was well worth it.  Less than one minute with this thing and my frozen water line is running again.  Forget about microwaving the water.  I just ran a glass of hot tap water and drew it into the syringe.  Only took a couple of refills and I could feel the tube advancing as the hot water did its work.  My compliments to the inventor for a simple elegant solution.