It tends to check sometimes if you yank the bark off too soon. If yours has been cut for a month, it's probably good to go. Let it dry until it doesn't stay bent when you bend it and loses that "spongy" feel. Stripping the bark will help it dry quicker if it doesn't check. You can hand straighten them every couple of days while they're drying and often have them good and straight by the time they are dry. Rose shoots have a pithy center, so just like cane, you need to get shoots that are a couple years old-the newer ones have thin walls and spine really low. They make good arrows, and if it's got good thick walls, you can plane them down to the diameter/spine you need.