If your friend doesn't mind, and if you don't care about sitting there for a few hours then go ahead. Just make sure you take a break after every 3rd kill. I'm pretty sure honor farming isn't banable anymore with the anti-camp system. But before you do this I would open an in-game ticket related to this. What I do for my honor is I just sit outside Deepholm and kill most people on the opposite faction. It's the fastest way. If you're going for honor it's going to take a while.