You don't need any catalysts. Getting back outside is done by successfully convincing the feeder to help you escape. But the game does seem to be over if you entered the facility without an established feeder relationship and so are assigned the special 5th feeder personality, because your chance to convince her are 0% after the first two tries (which are 5%). Unless you're really lucky, this situation is a total lock on that save! I'm fine with this because you have to really go out of your way to end up in this spot.
What I like most about the player WG option in this game is how closely the player's experience mirrors the experience of the girls when playing the game normally, this was something that was done very well by the developer. At the narrative endpoint of the girls in the facility, they're not in any state to convince the player to help them escape. So, in my opinion, the same should be true for the player.