I fully support the use of eco-toilet but I do not endorse the idea of converting human excreta collected from eco-toilets into bio-fertilizer. As far as my knowledge goes, some countries including Afghanistan use such manure. But the side or adverse effects of crops and vegetables grown by the manure on human health are yet to be known. In fact, not all the technologies are good for humans and it takes a long time after the use of a technology to figure out its adverse effects on human beings. For instance, tube-well has contributed to the creation of a serious health problem, i.e. Arsenicosis. Recently, researchers found that arsenic is being deposited in rice plants during nutrient uptake, thereby putting this hazardous element into the food chain. Again poultry litter also contains good amount of arsenic which is now widely used as fertilizer in our country.
I think, specific research should be conducted to ascertain the actual effects of these bio-fertilizers before recommending their use on large scale.