Ah!  This is something that is not explained too well in the instructions
and I'm sure has turned off many a would-be gravy maker.
 
The trick is - blend the chicken AFTER cooking it.  Raw proteins are
very, very sticky; essentially glue as you discovered the hard way.
(I learned the hard way, too.  I just gave up before my blender did.)
Cooked proteins don't tend to tangle up with each other the same way,
and so blend without smoking all of your small kitchen appliances.  BTW,
also don't dump all of the Metamucil in the blender at once with the hot
chicken.  That will ALSO earn you a smokin' blender.
 
If you cook the chicken by some wet method (pressure cooked, boiled,
stewed, etc.) it will soften the bones so that your blender can handle
them easily.  Even the toughest bar blenders (and commercial bar blenders
are the best, by the way) will have some trouble with the largest raw or
dry-cooked bones.  Wet cooked, they're no problem.
 
Cooking and blending the bones IS recommended....that gets you the
wonderfully nutritious marrow inside them.
 
roger
[Posted in FML issue 4596]