The archives over at Speypages talks about it around 2004 giving a lot of credit to Simon Gawesworth. There were a few threads that asked about it but noone replied specifically about the OOZLUM. But I'm sure you already knew about that. Lots of talk about this being a useless cast.
So I checked Simon's older book. It's in there. You basically lift the line from the water, and make circles with the rod tip over your head; like a helicopter (the rod would make a narrow cone as viewed from the side; with the narrow part of the cone being your hands ), keeping the line airialized , then cast.
OK. Thanks. I guess everyone has tried this cast in the early stages of learning how to spey cast, without knowing it had a name. I know I did. Just spin the line around you head until it eventuallly collapses on you and you stand there looking stupid. I've even tried figure 8 version of this, too, but now I suspect there is a name for this, as well. If not, I'll give it a name:
"The Crazy Eight spey." Hey, it's my cast, and I'll name it anything I want.
And who can say that the Oozlum or Crazy Eight doesn't have uses on the river? Suppose you're being attacked by a bunch of birds or cayotes or hienas while setting up for a double spey on the Skagit. Well, just turn that upriver sweep into an aerial or figure eight above your head and scare the animals away. This can also be used on a river full of plunkers, but I don't want to start an arguement.
Simon Gawesworth demonstrates the Oozlum Spey cast on the Rio DVD "Rio's Modern Spey Casting" Chapter 16: Weird casts on disc 3.
Gawesworth goes to great lengths to explain that the Oozlum is not a practical cast but a good line control exercise (so you don't end up with the line wrapped around your neck, looking like a fool). The technique is somewhat useful to learn line control for practical casts like the Jelly Roll. For some other usable weird casts Google the "Ompalompa" and the "Sea Dragon".
Yes, I just finished viewing Simon's three DVD series, and I've completed my journey to understand the Oozlum. It is a very useful cast for learning line control. It teaches you that a backcast can be thrown anywhere--as Simon explains. Learning the Oozlum is a key to freeing up your style and blending casts together. After reading about it, I practiced with an 8 foot 4 wt in the backyard. My cat started chasing the fly around like a tether ball, then I would drop the "anchor" all over the yard to get the cat to chase it some more. It guess it works on fish, too.