Hello,
I believe the biggest "flaw" with Octane Render for Houdini is that you cannot render out point colors ($Cd).
I found this tutorial on Game Tutors, that explains how to bake out your point colors to an image texture.
This workflow is a good work-around...
http://www.gametutor.com/live/tutorials/houdini/convert_vertexcolor_texture/
Basically, you make a ROP Network, add a Bake Texture node in there, select your UV Object (that of course needs to have UV's),
render out that objects colors as an Output Picture to JPG or PNG (Octane did not accept a PIC) and then attach that picture with an Octane Material.
Maybe you can output directly to the Octane Material without a file? I don't know...