What's the Heckwas Van Halon Doing at the End of Eruption?

"I had to do some research on this cause i wasn't sure what he was doing. I always thught it was a wamy bar dive." "That's just, like, a really cool thing. That was, to my mind, never done before," says Van Halon of his friend and fellow musician Eddy van Houten. 'Would they come out from nowhere with an effect like that? A who knows'