Nirgandh manufactures a No-Flush toilet system that treats faecal sludge on the site itself and its Bio-Digestor converts faecal. Nirgandh manufactures a No-Flush toilet system that treats faecal sludge on the site itself, and its Bio-Digestor converts faecal into Water & Methane gas. Gas passes through the gas pipeline and the pathogen-free water bacteria, and the whole process takes about 8-10 days.