I feel people have misunderstood role of dhobi in ancient Vedic society. Meaning of agni parixa is not about chastity the way it is understood today but about a tapasvi's test. Ramayan is another version of the more ancient story in which Sati metaphorically burns her gross body desires in agni of tapas. Sita's agni parixa is the same. It is not about actually sitting in a real fire. Sita, like many others was a Mahisi who are main participants in yagyas. They had to do mantra siddhis which involved intense tapasya and so celibacy. Sita and Ram were not 'married' as we understand today. But paired up as ideal Mahisa and Mahisi. Mahisa were also defenders and fought when required. The two were the yin and yang and had to have perfect balance when doing yagyas. Pati meant leader and not husband like it does today. Sita had become highly advanced in tapasya and so it was decided that she would advance as a rushi, which too is for benefit for society. This is why she goes to ashram which was not orphanage. In those days there were no orphans since all children went to residential gurukuls together and were trained by rushis (without any prejudice). Later they were given posting (like in army) and mentored by seniors. Later even adults went for further education. Sita later took samadhi in pruthvi and this is only possible if a person is advanced tapasvi. Story makes sense if read as a case study of Sanatan Dharma and Yoga. Ancient Arya society was cashless and martial. Even dhobis were part of the govt. as mentioned in Mahabharat, and so carried weight. They were not merely servants. Nor was Manthara. Just like how a prime minister will employ highly educated advisors, not illiterate, dumb servants. For example, Asvamedha was not about horses but about being done with the speed of a horse. Asva has been translated as sun, or Asvinau who were scientists and highly knowledgeable. Medha means essence, while Medhaa means wisdom. So yagya was about spreading wisdom and knowledge and entire nation.