From my experience, nasal exercises are only done when septum work is done. When it's a revision and only the tip is being worked on, I don't think there are any exercises involved. I wasn't told to do them ten or fifteen times daily though. I would love to find out if that's the average recommendation or not.
As Robyne said, you should really talk to your plastic surgeon about this to find out. A rhinoplasty forum is not the same thing