true, the last great marketing campaign was by jefferson hawkins selling dianetics. It did create a boom in book sales.That is also a bait and switch from the start. Dianetics is based on the concept of mental therapy very much like Freudian psychology. There is not spirit or thetan involved. So they are trying to rope people in by avoiding the complications of spiritual concepts and conflicts with people's religious beliefs but Dianetics is practically an obsolete afterthought to Scientology corporate. It is just a hook to get people into Scientology which is entirely based on the concept of spirit aka thetan. And of course we now know that even Scientology is a bait and switch for disembodied alien body thetans as the fundamental concept for fixing what is wrong with you on the OT Levels.
Dianetics isn't advertised very much anymore and the Superbowl ads mainly promote Scientology but Scientology books are pretty wacky for raw public so I can see how trying to sell Dianetics door to door now would be a problem because of poor name recognition. Most people probably associate Scientology name recognition with Tom Cruise and South Park. When the stabbing happened in Australia I spent some time searching Asian news sights to see if they were picking up the story. There wasn't much but what there was always mentioned Tom Cruise. When Tom is gone that will pretty much just leave South Park.
Like PTS says, I don't recall selling door to door is hubbard policy.However, it is policy to send letters to any book buyers, repeatedly, and forever.