I found the next 3 paragraphs here:
http://www.americaspedal.net/fx33/From the manual: "The FX33 Buzz Box is known as 'the mother of all distortion pedals.' Inspired by the legendary Melvins guitarist, King Buzzo, the FX33 takes its incredibly nasty distortion to new and dangerous depths by adding an octavizer. This octavizer takes the distortion signal and drops it down two octaves -- producing an out-of-control chainsaw growl -- and allows you to mix this with the regular distortion sound."
Historical context: The Melvins are widely cited as the favorite band of a young Kurt Cobain. It is unclear when the FX33 was first developed, relative to Kurt's death in April 1994 and relative to the Dunlop reissue of the MXR Blue Box. However, given the success of the FX69 Grunge pedal, DOD management may have perceived that a pedal associated with the Melvins might likewise become desirable, even if King Buzzo never officially endorsed it.
King Buzzo's reaction (Guitar World, February 1995): "I had nothing to do with it. I mean, does my guitar really sound that bad? ... The guys at DOD are kind of crazy; I have to give them credit for that. A guy there was always bugging me at shows about how we got the sound on the Eggnog record. I used this thing called a Blue Box, an octave divider from the early Seventies. So this guy says, 'I want to design a pedal; we'll call it the Buzz Box and get that sound out of it.' But it wasn't so much that he wanted to do an endorsement or anything. I think he just likes the sound of it. So he came to one of our shows and looked inside the Blue Box. He kind of duplicated it and combined it with the Grunge Pedal in a new pedal. I have to admire DOD for putting out something that insane. Yes, the Buzz Box is totally worthless. It sounds like a vacuum cleaner."
So it was inspired by but not officially endorsed by Buzz. I had always thought for some reason he did endorse it. I'd still like to get one but now it's way less of a priority.