the getting straight part,atleast for me,is pretty easy.
i only have experience with red osier.
but this works pretty well.
when i have my shoots dried and peeled,and the neighbors are having a camp fire. i go over there with a handfull of shoots,grab a chair and be sociable.
i hold a shoot over the fire,yet close enough to get them hot,to the point you cant really hang on to the heated portion too long,keep rotating it while its over the fire.
when its hot just bend it the opposite way that the natural bend is,and go just past straight,hold it there for a couple of minutes and whala a straighter shoot,then you find the next spot and keep it up untill its relatively straight.
hope this helps
peace,
tim