re: the persimmon guy at
http://www.persimmongrove.org/IFFSnoop/IFFSNew1.html

Thank you Nancy, for your time!  But if you go to the end of his tutorial you see that the manual jobb of deleting the Halo is done by the smudging tool, INSIDE the model. Somehow he has arranged so he can edit the mask by EXPANDING it,  while seeing the result.

It seem to me that that techique would be useful, not only for getting rid of halos, but many other things as well.