I am implementing a "Watson wick" bio-filtration system as part of a project I'm working with on in East Hawai'i. What little info is online is at Art Ludwig's Oasis Design consulting site (Art is a premier resource for graywater design information):

http://www.oasisdesign.net/compostingtoilets/watsonwick.htm

There are some unknown number of these designed by Tom Watson in Southwestern USA locations that have been working fine for a decade or more. I'm not aware of any (yet :-) in our area.
I'll be talking with Watson to get his ideas on issues relevant to our different climate, and documenting this implementation for demonstration purposes and proof of concept.

Meanwhile simple, inexpensive/DIY composting toilet and graywater system designs are well known and demonstrated here and globally. It's easy to find out what exists and what works. What isn't easy is changing technocratic and fecephobic cultural patterns and habits so that what exists and works is "legal."

cheers,
Jo