Fu Manchu was using the wire to pick the door’s lock. Fu took the wire out of his lip, stuck it in between the door and the door frame, wrapped the wire around the latch, and fiddled with it until it opened!
In Stones’ own words, “Nobody taught him this. Not only did he make the tool, but he put it in a place where I couldn’t find it. He was smart enough to know that if I found it I’d take it away from him.”