Hmm... I don't have that one, so I guess I'll have to go dig it up. One of his CDs (maybe it's "Satch Plays W.C. Handy"?) has a great outtake that came out during a mike check which they resurrected for the CD release. Paraphrasing from memory...

Engineer: Could you say something into the mike?

Satch: Umm.. hello? You know, when I was a kid, there was this alligator that lived out in the swamp, and my momma told me to go and fill up a pail with some water. And I said, no way am I gonna do that, that big alligator's gonna eat me up! And she said, no, he's more scared of you than you are of him. And I said, momma, if that alligator's as scared of me as I am of him, then that water's not fit to drink.