"It is clear that such knowledge is not in the public domain."
The opposite is true. People are simply discouraged from learning information that can reduce the power of thugs to project force against them.
A boy scout some years ago attempted to make a nuke in his garden shed. Sadly, despite the basic plan being functional, his safety protocols were insufficient to prevent being fatally poisoned in the attempt. Children are able to gain this information without particular sophistication, and it is not possible to suppress nominally.
Going forward, greater functionality will be possible to individuals as a result of technological advance, and in time institutions are going to be prevented from projecting force to continue parasitizing civilians. Freedom is coming.
I say he needed a set of OZK