Yep, shooting hand straightened shafts will undo some of the hand straightening, but the arrow will fly straight for the first shot.
There are a few wood species that will hand straighten and stay fairly straight when already dry. Birch is the best example and the easiest to get. Locally, I've had good results with Roosevelt Weed and Yaupon Holly. Of course, like Pat said, if you hand straighten when the wood is green it works better.