Recently i discovered my walnut knife magnet was putting some ever-so-fine scratches on my knives and did this mod with cork. I decide on using a stainless bar since they seem to be more powerful. I think it'll work better than my wood knife magnets, since those have a bit of slippery-ness to them. Not sure if this is a "new" idea or not, but thought i'd share.
Here's the cork (link) and the knife magnet (link)
Here's the cork (link) and the knife magnet (link)