Toilet Challenge as ISRU

In the news lately, Bill Gates has issued forth a challenge (actually a year or two ago but for some reason in the news) to create the next paradigm in hygiene technology.   The challenge reminds me of the NASA efforts in what is called In Situ Resource Utilization or ISRU.   The basic idea is that when going to other planets, you can't take all the stuff you need, but you would need to make whatever you need right there on the planet.  Thus even on other planets such technology as Toilet 2.0 would certainly be required (what no sewers!?).