From What I recall, legal slavery continued into the mid 20th century in Saudi Arabia (1962) and Oman (1970). Its recent enough that there must still be living survivors of it. Has there been any attempt to document there experiences, like the US did with former slaves in the 1930s?
If we include older portions of the broader Arab and North African slave trade, then there was a demand for books about the experiences of escaped or freed slaves. For example, John Smith (of Jamestown fame) wrote an account of his enslavement and other life events "The true travels, adventures, and observations of Captaine Iohn Smith, in Europe, Asia, Affrica, and America from Anno Domini 1593 to 1629: his accidents and sea-fights in the Straights (the title goes on but you get the idea)". However much of those recollections were exagurated for greater entertainment value, as were other similar narratives.