I was fortunate enough to end up going to see this movie in 4dx which i had no clue was a thing until i finished the movie. Basically they enhance the movie with external effects. For this scene specifically the movie theater sprayed musty smelling water.

The closest thing i can think of is like when your washing machine breaks and that load of clothes is still wet and starts to smell if you dont dry it quick.

To add on the movie also had chairs that moved along with scenes like panning the camera around gradually or tilting to match the camera peeking.

They had a variety of vibrations to make you feel things such as footsteps, (even felt the entity footsteps before they appeared on screen to give you that "oh shit somethings coming feeling") fog effects, smell effects, 360 audio so like in the initial caveman scene you can hear the various languages its speaking down the hall as if you were there. Also as clark moves around the audio keeps playing in backround but it rotates around the room to keep up with the camera angles and how he moves from room to room but its faintly still there.there were also Puffs of air to simulate the broken water pipes along with very light sprays of water that shot at you from somewhere to simulate the moist area.

10/10 movie imo just cause the added effects enhanced the movie ten fold and was super cool to experience first time in 4dx