Using principles from '5 Core Methods of Innovation', I have identified that the material "LIQUIGLIDE" could be a key to creating such a toilet requiring no flush/water. Liquiglide is a structured liquid, it is rigid and can be applied like a solid, but has a surface like a liquid.
A coating of Liquiglide inside a plastic or glass container ensures that the surface becomes completely non-sticky. When it was applied inside a ketchup bottle, there was not even a drop of ketchup that could stay inside the bottle once the bottle was turned upside down.
(News source: http://articles.timesofindia.indiatimes.com/2012-06-01/india/31958462_1_new-toilet-flush-toilet-practice-of-open-defecation )