The rust erasers are a rubber matrix with silicon carbide grit embedded in the rubber. Personally, I'd avoid using them on nickel-plated diamond hones, as the SiC grit could erode the nickel over time. I'd opt instead to use just a simple pink or white pencil eraser, of which their 'abrasive' is a lot less aggressive. Some or (maybe) all 'pink' erasers use some iron oxide embedded in the rubber, and it won't be anywhere near as aggressive against the nickel plate on the hone.
An old toothbrush and some dish soap, or Comet/Ajax powder, or Bar Keeper's Friend & water work well for cleaning nickel-plated diamond hones. The oxalic acid in BKF will dissolve iron swarf, but is essentially non-reactive with the nickel plate itself. So even it won't hurt the hone.