Happened to codyslab, videos taken down now (but still on archive.org) of a uranium purification process and possibly nilered,no way to prove it but he had a 'making rocket fuels: part 1' that was never followed p on. Not totally sure though as people like BPS space on yt have some pretty in depth tutorials on solid rocket motors (does explicitly censor how to make the ignition component)
Uhm, there are plenty of videos about making solid rocket fuel. Model rocketry doesn't need any special permits until you get to launching large rockets.