If you hate documenting your source code, you are not alone. I also hate it. There is no way to avoid it. Luckily, there are free tools which make documenting your source code a bit less frustrating.
Dual quaternions are relatively new. You don't find them in many computer graphics books and very few people use them. Nonetheless, it is a mathematical concept you should be aware of if you are planning to develop a game engine.
To develop a game engine, I knew I had to learn a lot of math and programming concepts. However, learning how to model a 3D game character was never one of them.