In her short story "Sweat," Zora Neale Hurston decided to make Delia a washerwoman to illustrate just how miserable and harsh her life is and has been. Her job is a metaphor for the abuse that she receives from her ruthless and unfaithful husband, Sykes. The job entails hard, physical labor and requires one to be meticulous when cleaning customers' dirty laundry. Even though the work is hard, Delia takes pride in what she does. Delia applies the same patience in doing the laundry that she displays towards Sykes. The difference is that she gets rewarded for her work while Sykes's ill-treatment has no benefit whatsoever. It becomes clear that Delia has been tolerating her husband's maltreatment for almost their entire marriage.
Hurston probably also chose this activity to demonstrate the irony in Delia's life. She cleans others' soiled laundry, but she cannot get rid of the metaphoric filth in her own. Sykes is what soils her existence and makes her unhappy. Even though she, through her labor, is solely responsible for the upkeep of their household, Sykes does not appreciate her efforts or show gratitude. He exploits her tolerance and verbally, emotionally, physically, and financially abuses her. It is a pity that she cannot rid herself of the bane in her life as she so expertly removes the dirt in her clients' laundry.