Still trying to find the artist responsible for the original commercial recording of "I Washed My Hands In Muddy Water," here's an email received from Joe Babcock himself:

"I don't know exactly when Okie Jones and I cut our demo on "Muddy Water" but it would have been 1965. However you know that this was not a commercial recording, just a little demo that we cut in Marty's studio to give to Vic McAlpine to plug the song. He took it over to one of the record companies but later found out Stonewall was cutting that week so went back, got it and took it over to Columbia. They wanted it and Stonewall cut it right away. Stonewall told me lately that he ends every show with it now. Joe"

So it looks as if Stonewall Jackson was the culprit.