The 3 day pay or quit notice is to pay or vacate. Make sure it is posted prominently, and send a copy by mail as well, and a copy certified. While you are there posting observe the house outside to see if there are any other signs of move out. I would wait until the 3 days are up and do two things. Prepare to file for eviction, and post a 24 hour notice to enter. After the 24 hours are up enter to see if everything is moved out. Then you go from there.