Like Pat says, you don't have to remove prop twist if it is balanced between the two limbs and thus offset each other. Like Pat, I seal the wood with shellac also before steaming. I also seal with shellac before dry heat and use a high melting point oil, such as bear fat over that to help moderate the intensity of the dry heat,aka keep from scorching the surface. the shellac keeps the heat from driving the oil deep into the wood.
Like Roy said, get it close to bow dimensions before tweaking with heat of any kind. Took me awhile to get that figured out on my own.
Steam is generally the safer bet if you are less experienced bending bow staves. But heating the full length of a stave with steam requires an apparatus of some type, which are not hard to build, but is another step.
Good luck!