If you had some fuel to burn in the dish you could do it. Pour the alcohol from Abber's flask into the dish, strike a match, and light it. You can then put the ball in the flame and then put it on the spike. Then you can open the vent with the coated spike and crawl out. Keep moving through the vents away from your cell.
Time is of the essence.
Hmm, big fan blocking the way. If you could jam it with something you could probaby slip through. Well, the guards are on your trail, you should get hidden quickly. When you see the old woman beckon you, enter her house. The lady wants to give you something, you might as well hang around till she finds it.