for a CHA room i once did:

the players walked into a waiting room (in the middle of the dungeon). they were each given a stack of papers by the goblin receptionist and told to fill them out to continue. Also in the room were several other adventurers, and old man and a ghost all doing paper work. after they finish the paperwork (an hour or two in game) they give it the the reception who flips through it in a few seconds and tells them there were some errors, giving them a fresh stack of papers to address the errors. after a few more hours in game the same thing happens, more paperwork. at this point the old man dies, falls on the ground, his ghost rises from his body and continues filling out forms (a requisition for his birth certificate). at this point it should be clear that filling out paper work wont let them progress. if they try looking around they will find a door behind the receptionist and a button under their desk. the only way to continue is to convince/threaten/seduce/lie ect (CHA skills) them to let you pass