I prefer NAC as a Lead mobilzier since it appears to be more tempered. That said the Lead mobilized by SSKI is already within the body, so DMSA is far better than the Indian Gooseberry.
Now it helps but just takes longer, where it shines though is by removing Lead from the intestines before it enters the body. If you are using my "Bean Commandments" 24x7 this is noticable since less Lead actually enters the system..