What are the solutions offered to Bakha towards the end of the novel?

Much of what they say goes above Bakha’s head, so elevated are their vocabulary and ideas. However, he does understand when Sarshar mentions the imminent arrival of the flushing toilet in India, a machine that eradicates the need for humans to handle refuse. This machine could mean the end of untouchability. With this piece of hope Bakha hurries home to share news of the Mahatma’s speech with his father.