SOG SYSTEM Chemical free operation of your toilet system The SOG toilet ventilation kit converts your Thetford toilet into a chemical-free system which is not only a completely green solution but also banishes smells from the interior of your unit. No chemical smells and no smells from waste matter, even during use of the toilet. Toilet chemicals are no longer necessary and optimal decomposition is guaranteed by the increased flow of Oxygen. You can also use ordinary toilet paper. Supplied as a very simple diy-fit kit.