I should mention that twists that are less then 30 degrees are rarely a problem.
Fixing a propellor twist is easily done with this set up. First, floor tiller the stave so that it is thin enough to bend.
Second, attach the wrench as shown to which is attached an empty milk jug. Third, with a heat gun heat the stave so that it is hot to the touch.
Keep the heat gun moving.
Fourth, add water until the twist is removed. Going a little past is a good idea.
Be sure to let the wood rehydrate for several days before resuming tillering.
How long depends on where you live and the relative humidity
Copyright by George C Tsoukalas