One every nice things that DGT has done is to invent a real time reaction analyzer that observes the reaction products as they are being produced by the LENR reaction in real time.
It has cost them a $million more or less to develop this piece of test equipment. Analyzing the ash after the fact has many pitfalls. For example, if the Rossi reactor operates continuously for 6 months in a sealed mode, the nanostructures(nickel nanowires) that support the reaction will have suffered little change in terms of transmutation. Where does all the ash go? Most of the ash might be deposited on the walls of the reaction chamber through some sort of vapor disposition. Where you look for the ash I fear will distort the overall picture of the reaction.