I would say that it could still work, but neuronavigation would increase the chance and possible the effectiveness of the treatment. However another possibility is that you belong to the people who don't respond to TPJ-stimulation.
I think dreamdm's history was a bit more complicated than having ECT and directly afterwards the blank mind. I'm not sure, but I remember that it was more like that it set something in motion that ended after some time with the state he is still in. This would raise doubts it really was a direct effect of ECT or even brain damage.But if your blank mind was caused by it - I think I will not try it for my blank mind.