Oblesh speaks about how the necessity of sanitation created the task of manual scavenging, and how the affluent class used to define a lower caste to undertake this task of manual scavenging. This necessity perpetrated the exploitation of the castes that has spanned generations.
And that this is still practiced today, even though the original necessity of sanitation has been mostly been addressed by modern toilets. He says it is important to have proper sanitation infrastructure in place so that the necessity is meet, this task of manual scavenging will no longer be relevant and die away by itself.