Morwenna Banks did a doc. for C4 about "The Comedy Of Hate" about 1989, which had something in it about him. I think it's discussed somewhere in SOTCAA, but I can't remember.
Clay seems to be the US stand-up that no British stand-ups laud.
Matt Stone and Trey Parker from South Park said that he was a really mad subversive comedian, closer in spirit to Andy Kaufman's "Tony Clifton" than Bernard Manning.
I remember him breaking down and crying on oprah or one of those shows a while back. Maybe we all misunderstood him. But let's not forget that his success was down to the redneck bigots that attended his shows and bought his records. Whatever. Let's NOT start comparing him to Andy Kaufman, who was patently one of the greatest comedians ever to walk the earth.
Basically ripped off Sam Kinison's act, and whether you loved or hated Kinison, at least he "meant it, man". Clay, on the other hand, once he realised that audiences were deserting him, started talking about it being just an act (translation: I'm not responsible for my own material), then started being in rubbish sitcoms. I saw him in a thing called Bless This House on Channel 4 a few years ago (and no, it wasn't an American remake of the Sid James/Diana Coupland show). It was hopeless, and he was trying to be Mr. Nice Guy. Imagine Jerry Sadowitz in The Upper Hand? Exactly....