Lived to tell, or wanted to tell. Its not something you'd go around telling your friends about, especially considering how superstitious (some for good reason) the three seas are.
I probably has happened, yes, but no written accounts of it happening and its affects doesn't seem unreasonable.
Kellhus probably tested it. Forced/convinced prisoners or subjects to eat a diet of only sranc and see what it did to them. How much you needed to eat, for how long, for anything to happen, if anything at all. If effects, what they were and if they were permanent if you went to a normal diet, or only imbibed some minimum amount. And then, kill all the participants so no one (consult especially) knew what he was doing.
Quirri/chanv/sranc remind me of Limitless' "NZT". Maybe he found a way for himself to mitigate or eliminate any unwanted side effects. Not probably feasible or worth the effort to figure out how to keep the whole Ordeal alive, but maybe a select few... like say a school or two.