Johnny's famous "chicka" part of the thing was not a drummer but was done by placing paper between the strings of his guitar and using it to make that sound in the studio. "Walk the Line" featured this, don't know about Folsom.

You're right Mac. However, the way I used to do it(get close that is), was to mute the bottom 5 strings with the palm of my right hand and do alternate picking on the 4th and 5th strings, assuming you're playing in the key of A. My brother was playing rhythm guitar along my plucking. It was close and sounded alright. But, that was years ago, just sayin'.