“And if after giving the tochocho they still are doing the aveira, you are halachicly *required* to publicly humiliate them until they comply.”
(Pardon the cynicism) I can just see people lining up and saying hinneni muchan umzuman already. A hetter to publicly humiliate someone.
There is a mitzvah of tochacha, which comes with a qualifier “lo tisa alav chet”.