This is the "gay" version of Whipping Post. I hate to see anyone mocking the Allman Bros.'s authenticity, but the song begs for it - so to speak. Plus, it's kind of amazing to hear music that is both accomplished and entirely satirical.
But, in truth, I'm sure there is some reverence in Zappa repeatedly covering Duane Allman's song. As Zappa described it in 1983,
"It started about ten or twelve years ago when some guy in the audience at a concert in Helsinki, Finland, requested it. He just yelled out "Whipping Post" in broken English. I have it on tape. And I said, "Excuse me?" I could just barely make it out. We didn't know it, and I felt kind of bad that we couldn't just play it and blow the guy's socks off. So when Bobby Martin joined the band, and I found out that he knew how to sing that song, I said, "We are definitely going to be prepared for the next time somebody wants 'Whipping Post'--in fact we're going to play it before somebody even asks for it." Source