Already answered that on the previous page. It unlocks a few miscellaneous scenes, nothing major.
Top left side of the screen you should see a series of buttons. The second from the left should look like a shopping cart...that's the slave market window. For reference, the buttons from left to right should be the Main Menu, Slave Market, View Slaves, Stations Management, Galaxy Map, Diplomacy, and Owned Bodies. Note that some of those do not appear initially on a new start but after certain requirements have been met (you need a desk in the suite before the Galaxy Map can be pulled up).
If you're using an old save made from when the bug first surfaced, it will still do that even with newer versions of the game because the issue is carried over in the save file itself. Your best option is to start a new save. There's a way to manually fix the issue yourself to keep the save, but I do not know the process. As I recall, I believe you have to open the save in a text editor and track down each ship's data line and change a true/false flag.
If you are referring to workers, bioreactors, and fuckdolls, options to buy them appear at the top of the Slave Market window.
