I want to try this and have read some about using a more powerful magnet to do it by rubbing each pole on each side of the old diaclone magnet. So far no luck, but my more powerful magnet may not be enough. I want to get the Neodymium ones that seem to good for this task. One thought I had though was this, why doesn't the old diaclone magnet stick to my bigger magnet? Even if it doesn't attract metal itself it is metal so shouldn't it be attracted to my working magnet? I just hope this isn't a sign that the metal properties are too oxidized or whatever it is that happens over time.

 

Since the magnet is just metal couldn't you just run it through a magnetizer/demagnetizer like one would do with a screw driver tip?