Here is a web page that has Hubbard's actual voice telling the Xenu story:
A Scientologist told me years ago that there is a Hubbard lecture about the between-lives area. The Scientologist told me that souls from Earth instinctively go to the between-lives processing areas after the bodies die where the souls are zapped electronically and placed into ice cubes. The ice cubes are put aboard UFOs which take them back to Earth where the cubes are dumped into the oceans. The ice cubes thaw which allows the souls to escape and seek out new bodies. The Scientologist claims to have witnessed a UFO once over the Pacific Ocean dumping ice cubes. I can't say that I'm highly familiar with all of the UFO literature, but from the bit that I've read I don't recall any other witnesses claiming to have seen a UFO dumping ice cubes (although I could be wrong).
One thing that caught my attention in Hubbard's Xenu lecture is that his first priority is to get Scientologists to "own" the planet, not save it. Somehow the planet will be saved when Scientologists "own" it. I really think he had the crazy goal of becoming Earth's ruler by getting Scientologists to "own" the Earth. He didn't just write 1950's space opera, I think he was living it in his own mind.
Yes, the goal of $cientology is to clear (own) the planet.
This reminds me of an "event" after I had shortly joined the CO$. The speaker, I'm thinking he was 16, was claiming to be the youngest OT8 at the time. He went OT8 on the Freewinds. Anyway, he asked for a show of hands of how many aged 40+ remembered 30 years ago. Some hands raised. Then he asked of those under 30 (which I was at the time) to raise our hands if we remembered 30 years ago. No hands were raised. The OT8 speaker said that it was "between lives areas". He said that something really bad would have to happen to make a Thetan forget an entire lifetime.