I am no longer a huge fan or red osier (tons around these parts). In my hands ocean spray makes a far superior hunting arrow. But with the RO, as you dry it (remove bark right away), shafts will go through three phases. First, its green and totally elastic (i.e. can't be straightened). This can last a week or so, but depends on your RH etc. Phase two starts the plastic stage, when you can easily straighten the shafts by hand. Do this a few times a day. After several days they will be too dry to straighten easily without the application of heat. This is the third stage. If you understand which phase your shaft is in you know how to proceed.
Dave