You seem to be implying that modern third world is so far behind so as to resemble 18th century Paris. While I agree with you that the quote in parent seems exaggerated I don't think even a modern very poor country will stink like 18th century London and Paris. 18th century was a time of horse driven transport and little to no sewer system. The main stench would be from those two things which in modern times is mostly absent even in poor third world countries.