Well, the person who told me about the abrasive compound and toothbrush, also said that sonax will NOT get this off. This brake dust is baked on hard.
The before/after you sent, is not what I have. What that picture shows me, is someone with a couple day of brake dust that came off with chemicals. Brake dust comes off with soap and water. Baked on/Build up of brake dust, is what my wheels have.