A trip report of the Smileys climbing the Steck-Salathe route on Sentinel Rock in Yosemite. Here's a photo of him trying to get through the "Narrows." This is the section of the climb they called "the pain closet." He didn't make it on his own; his wife used a 3:1 pulley system to help get him through the tightest spot.
Here's a description of this spot on mountainproject:
"One must drop one's feet and figure out some way to make upwards progress in a squeeze chimney using only body parts from the hips up. I managed this by using the back of my head on the back wall to pull my body upwards while simultaneously exhaling, then taking a deep breath to hold that position while I groped for a higher purchase with the back of my head. Hey, it worked. Gear for inside The Narrows really isn't necessary, but a fist-size cam (#3.5 Camalot/#4 C4) works well to protect the initial moves. For most of this you feel pretty alone with only the sound of your own gasping, and the tinkling sound of the hangers on the old aid bolts blowing freely in the wind on the outside of the slot, for company. Perhaps you'll wish you were out there hanging from those bolts, but persevere -- eventually things will start going a little more quickly."