Chew The Meat And Spit Out The Bones Meaning

Example: To take in a great deal of information and selectively disregard some of it as invalid or inapplicable
2002, A. Frank Goepel, A Realm Without Rules, page 116
  Do not swallow every story that is told. There may be a grain of truth somewhere in all the myths, but chew the meat and spit out the bones.