If you have the need to cycle through several different messages on an IVR, you might consider having all recorded on different IVRs, then sending callers to the desired one by using the forwarding options of an extension. That way someone can easily change the destination as required.
Some time ago we wrote a custom "job line" Call Flow Designer (CFD) application. The employee calls the CFD extension, is prompted to record the new prompt, and when confirmed, associates the new prompt with the Digital Receptionist.