I was writing a Hogyoku guide (here). Feel free to add anything. (I'm probably going to need a lot of people if I want to fill this thing out).
I'm trying to be less generic and gather actually useful info about it, particularly how swallowing and leveling works and all those fun goodies. That was my main reason for writing it, anyway. I don't feel people generally know much about it.
Feel free to contest any of my assumptions as well. I've only written what I've personally observed through testing.