I like the tubes you use in a golf bag. If you go with PVC, cut the pipe lengthwise, then rasp any sharp edges off the ends. Duct tape it on, but don't leave it long. Couple of days at most.
They'll usually come around in a few days even if you don't do anything. Just make sure momma's sticking with them. Flexing the joint and straightening it makes me feel like I'm doing something useful. Might be a waste of time.