Aaron, that will be fun to watch. I had last fall the left over of the Desert King that I sent out to many. the piece of wood was like a foot and half rod. I wrapped in moisted newspaper and put inside plastic bag for about a month, then, I decided to plant it on a 5 gallon pot. I use a 5 gallon water bottle with no bottom as the top. I covered the top with a little garden pot, so there was som 'hot air escaping'. The thing grew and grew. It is one since stem as fat as my fatty fingers and is about 3 feet tall now. I am allowing to grow single as it is part of my own experiment.
in this Brazilian paper, they say that roughly 20 a 30 cm in length and 1,5 a 3,0 cm de diameter is the ideal for greenhouse starters, and 30 a 40 cm e diâmeter about 1,5 a 3,0 cm when planting directly on the field. Large cuttings have more juice of life in them.
http://www.fruticultura.iciag.ufu.br/figo.html