Holy ashes of Narl Gatu
Narl Gatu is the world of origin for the Nul Nul. Their home world was turned into a nuclear wasteland during their last inter species war. The surviving Nul were united under the first Grey Nul and spread to other worlds, at first abandoning their now dead home world. The nuclear weapons that were used turned much of the surface into fields of knee deep ashes. Over the centuries the radiation is no longer lethal and Nul travel to Narl to bathe in the ashes to purify themselves and re connect to their roots..
It is strictly forbidden to take ashes from Narl Gatu . Except what clings to the body.
This "cling dust" is kept in metallic envelopes by those who made a pilgrimage to Narl Gatu and is the most precious property. After a Nul dies, he or she is burned to ashes and returned along with his "envelope" to Narl Gatu. Only those purified by the Ashes are allowed to return (as ash) to Narl Gatu.