What does "soap" symbolize in "Enterprise"?

In Nissim Ezekiel's poem "Enterprise," the speaker describes a pilgrimage which becomes increasingly difficult as the group of pilgrims that began the journey gradually disbands.
Towards the end of the poem, the speaker, describing a particularly difficult part of the journey, says that he was "Deprived of common needs like soap." In this context, the soap is a symbol of the civilized way of life that he has left behind. The journey has become so difficult in part because he has been deprived of those aspects of civilized life, like soap, to which he has previously become accustomed.
At the end of the poem, the speaker realizes that despite setting out on a pilgrimage to discover or come closer to the grace of God, "Home is where we have to gather grace." Being deprived of soap, which is a symbol of the civilized life, emphasizes just how far the speaker has come on his pilgrimage and how far from civilized life he has had to journey, only to discover that grace is best gathered, after all, at home.