text: "But the expression is 'walking the talk'."
  
  I think that's a mutated version of the original, which was, "You talk the talk but can you walk the walk," which I remember from the 1960s.  Stanley Kubrik put it in the mouth of one of his characters in Full Metal Jacket (1987):  https://www.youtube.com/watch?v=k-RduxAYCQM&lc=z121idl4pxayerjzp04cilt5kob2e5igu5w