While it's nice to provide various solutions like this I will throw some ideas:
1. There's no universal solution. Some will prefer to "scramble" the words in a way or another, some will keep them as they are. Keep in mind that you're complicating an existing solution and this can easily get the funds lost.
2. Keep in mind that if we can read and find inspiration in your solution(s), the potential thieves also can do so.
3.
3.1. The index-in-a-book solution is not original, it's present even in novels and movies (last one I've seen was a Sherlock movie).
3.2. The git solution is imho overly complicated.

I would avoid this kind of solution. Indeed, this makes the words hidden from thieves, but it also makes them hidden from friends and family. If an accident/trauma or a disease gets a bitcoiner into memory loss, he will no longer be able to recover his money, and nobody close to him would also be able to do so. For some this is a real problem, some choose to not care. Again, it depends from person to person.