This breakthrough is so obvious, it's a wonder it hasn't been built into all Thetford toilets. A small company called SOG has developed a third party, after market bolt on kits for cassette toilets, rotating bowl toilets and conventional drop toilets. OK, so how can it work with no chemicals? Simple really - exactly the same way the waste would break down without human help in the real world - using oxygen. The modifications needed are very minor. A surface mounted high volume 12 volt fan is installed on the outside door. A flexible suction line is fitted to the cassette - middle picture below. A micro switch is fitted to the blade mechanism.

So what happens? You open the blade before sitting on the toilet and the fan starts. This draws air down through the bowl PREVENTING any foul smells rising. As you "make more smells" they too are drawn into the cassette and then vented to atmosphere via a charcoal filter. This effectively stops odours actually escaping into the motorhome interior. Shutting the blade when finished "the business" turns off the fan. Now we haven't actually tried this system, as it was shown to us at the 2002 Brisbane RV Show.

SOG claim that you never need buy chemicals again! Now at $8.00 plus a litre this is an attractive proposition to all wee Scottish folk. Aussie Traveller is the Australian distributor and there is a lot more information on their site. The kit comes in at $298.00 - plus postage. The photo below was taken at the RV Show. As you can see it is slightly different to the brochure photos shown above. (June 2002)

What we don't know is what it smells like when you empty it - better or worse than the Thetford chemicals? If you were full timing we worked out it would take 300 plus days for it to break even, so it isn't as expensive as one would first think. You could save money by using any cheap disinfectant in the top tank. SOG neglect to point out in their otherwise excellent pamphlet, that using plain water in the top tank can cause algae to form which results in black specs each time you flush. You can of course avoid this by always emptying the top tank before storing etc. You can buy the inlet connection separately to fit into extra cassettes. We would be pleased to hear from anyone with real life experience with this system.