It depends on how severe the twist is. Most twisted limbs were caused in the old days, when guys tried to string their bows by the old step-thru method. This is how I used to straighten twisted limbs, back in the days when I had my traditional archery shop; take a wash rag, or small towel, and put it in hot water that you can barely touch. Wring out the water, and wrap it around the twisted limb. Take the rag off, and twist the limb in the opposite direction that the twist is. Keep doing this, until the limb comes back straight, check it by sighting down the riser. Once it is cool, it is safe to string. From here on, only use a stringer to string the bow. I found over the years, that once a limb has been twisted, it is very easy for it to twist again, if handled improperly. Hope this helps.
Mad Dog