Lets use that fat to make torches light and fire would both be useful
Find any stick like object (NOT INCLUDING CHEST ITEMS) to cover the top in fat and fire then start burning the webs
While your copanions watch, you grab a bone, laying in a corner or the mysterious room, and plunge one end into the burning fat. a strange, hollow wail emantates from teh bone. "Just our collective imagination" you mutter, reassuringly, as the wail echoes about the chamber. You stride out, wave the bone at the webs, and set them on fire. They take quite well. Soon, the hallway is filled with the merry sounds of crackling fire, panicked howling and thrashing, and your and fiddler's coughing. For a brief time, the corridor is filled with the merry sight of dancing flames, thrashing cocoon, and scattering spiders, whistling and popping as they scurry around. And then your vision is occluded by the thick black smoke that pours forth. You reel back from the heat and try to catch your breath.
"That's a surprisingly good idea! Good thinking there."
Just in case though retreat back from the entrance.
You stand well back, but the sheer volume of smoke catches you by surprise and you are caught up in the thick, oily cloud.
Provide a lightsource for my comrades by shining my stafflight and eyelight where they need to see.
Your light is helpful until the smoke becomes too thick to see through.