This reference shows one of several methods of producing Hydrogen Rydberg matter(HRM). This methid is based on the high pressure compression of hydrogen by the absorption of hydrogen into nickel. The nickel must be made receptive to hydrogen absorption through the fracturing of the nickel lattice by the application of various lattice stressors carried out over a long period of time. Rossi's fuel preprocessing method could produce both fractured nickel powder and HRM to be loaded into the reactor as fuel.
If you have any 5 year old nickel batteries, your in luck. You can extract(HRM) through acid treatment of their nickel electrodes.
One interesting coincidence is the mention that the extracted HRM is a fine gray powder as stated by the following:
As a result of the metalceramic nickel matrix dissolution, the portion of electrode submerged into solution, detached, and dropped to the flask bottom. The fallen portion had the appearance of the initial electrode without any changes. However during extraction from the solution and when the fallen portion was touched, it split into small crystals of grey color with metallic luster
Fine grey powder is seen in the Lugano test in the ash.
There are other mechanisms that can produce HRM as ECCO is theorizing. I believe that Rossi realized this when he understood that the nickel in the Hot cat had melted. Unbeknownst to Rossi before the Lugano test, there was another mechanism that could support HRM production.
I believe that the inclusion of mica used as an insulation between the wafer heater from the two adjacent fuel chambers produce HRM as a result of an infrared photon lensing effect that uses it hexagonal crystal structure to quantum mechanically catalyze HRM in the same fashion as graphite does. This is exactly what Holmlid is doing with graphite and iron oxide(both are hexagonal crystals) and laser light.