I would never call any progress in technology dumb. They are simply intermediary steps toward something that has practical application. I can see usage of this spray on silica in biotechnology in order to avoid contamination, filter organisms, and other means to prevent contamination and infection. However, to my knowledge, silica is a potential carcinogen (like many substances), so proper handling is required. I would not trust this compound in the hands of industry for mass production, due to the high likelihood that this would contaminate the environment, since it is in highly volatile form and the risk is in inhalation.
Whether this technology is more helpful than problematic is another issue. I see value in nanotechnology that simulates natural structures (biomimicry), and destruction in nanotechnology synthesized to serve man's purpose.