The knowledge of how to tie a noose hurts no one. Knowledge in and of itself is harmless at rest. As with all knowledge it’s what you do with it. Keeping people in the dark is an immoral solution to evil.
And AR-15s hurt no one. Yet they are purposed to have massive killing power against humans, and massively amplify the damage a single ill person can do. Hypothetically there could be some type of weapon that once discovered could end all life on this planet. If that weapon was trivial to build, it would take 1 person with that knowledge to end eveything. Human knowledge is a human construct, and shouldn’t be thought about in absolutes.
What knowledge is "in and of itself" means nothing because it exists in a context, the only thing that matters in the case of knowledge (or anything) is what's done with it and how it is useful