Hmmmm, to my knowledge, no one has tried. I don't know if that is because it is not feasible or if it is because no one wants to; two headed animals are valuable to private collectors and animal facilities.

The big problem in my mind would be that, left alone, this animal could survive. However, if you were to remove a head, that head would obviously die as a result. And with a combined nervous system, I'm not entirely sure how the remaining snake would maintain proper control. I'll have to look into it a little more; good question!