It is quite simple to activate the magnetic field of a keris. Just hold the tip to a powerful magnet for a few moments. If you then run a compass along it's length you will find that it now have a magnetic "north" and "south" pole. I do with with all my keris as part of a cleansing and re-alignment of energies.
Pusaka, prehaps i've got it backwards. You mention keris blades that are put in the service of a jinn. I had always understood that the jinn are put into the keris to be in the service of the owner of the keris. You sem to imply that the jinn controls the keris.
Likewise i still have trouble wrapping my mind around this concept of the "evil" keris. Why would an empu create a keris that is "evil" and would do it's owner harm? What would be the purpose?
