That would be an amazing bargaining chip. But, would it mostly sway the Intact who could be succumbing? The Erratics, their minds are so fucked, would they know to desire the Dunyain method?
Wilshire, if what you say is true, the Dunyain just have to be a Seswatha project to get the last Nonmen to help fighting Golgotterath. S doesn't know how to do it, but he knows if he sends so monks up into the mountains and let them work on the problem for a few millenia, they will eventually learn how to heal an Erratic.
On that subject, Erratics get that way from having too much experience. So the 'cure' could have something to do with purging their minds of most of what they know to have a coherent self and room on the hard drive to sustain them until another reset.