The propane torch?
My style of annealing involves holding the case on a nail in the jaws of a pair of pliers and spinning it with the fingers of my free hand in contact with the case rim. In lieu of other influences, when the case rim grows warm/hot to the touch it gets dumped in a container of water. What I did with this rig is to simply spin the wire between fingers until I achieve the desired discoloration of the case mouth, or forward half of the cartridge case.
FWIW, the case in the picture has been annealed.
