I agree that the Nakayama alone might not be enough to bring the edge back. My Hart Steel needed "refreshing" so I gave it about 50 laps on honzan slurry diluted and then went to just water until the stone was just damp. Shaved and did not notice a big difference in the edge.

Prior to my next shave with the Hart, I first gave it 50 laps on Koma Nagura, followed by the same as above. There was a HUGE difference and the Hart shaved much better than it had before. Smooooth!