I just found out that the phrase "walk the talk" is listed in Paul Brian's Common Errors in English Usage.
The correct usage is actually "walk the walk".
It says, "Aristotle’s followers are said to have discussed philosophy while walking about with him—hence their name: “peripatetics.” I suppose they could have been said to “walk the talk.” For the rest of us, the saying is “if you’re going to talk the talk, you’ve got to walk the walk”—a modern version of old sayings like “actions speak louder than words” and “practice what you preach.” Another early form of the expression was “walk it like you talk it.” Many people now condense this to “walk the talk,” which makes a sort of sense (act on your speech), but strikes those who are more familiar with the original form as confused."
But "walk the talk" is so commonly used in my working place now that it will be useless to change it. And reality is I truly wish people will just walk the walk or walk the talk and practice what they preach.