buddy has a 3 piece take down and he let the heat get to it so I'm gonna try and fix how would ya'll do it.
If twisted I'd just overtwist it little by little until it stays straight. Do it unstrung though.
I got slightly twisted upper limb. I keep it strung and just overtwisted it and hold it there maybe 30sec. I do this few times, when it seems to be ok I leave it over night before testing. Worked! Warm water maybe helps if twisted more..
This should be in PowWow. You'll get more help there, too. http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=6;t=007116