Re: Air Head Composting Toilet or Similar Mfg.
I have been using mine for several years now, and there is no way I'd consider going back to the traditional head. No more pumps, thru hulls , valves, hoses, clogging, breakdowns, etc, etc. I built my own for under $25 worth of materials. They are quite simple to build, but C-head has one for around $400. As others come on line , expect the price to continue dropping, until China or India starts making them for under $50.
I dump my 5 litre liquids jug every two days, but have gone 6 weeks, before dumping the solids container, usually back in the bush. In hot weather, dumping is far less frequent. In winter, ading Pooh powder absorbs any liquids in the solids, and helps a lot. Google Pooh powder.
As dumping liquids overboard is environmentally harmless, doing so is no ones business but your own. Some use a cockpit drain for privacy, and to keep it from those to whom it is non of their business.
Brent Swain, Yacht designer, Builder, and author of "Origami Metal Boatbuilding"