Most of psychology and psychiatry demonstrates very little beyond the obvious. What part of the truth that has come out contains the admission that there are certain screw-ups that are simply unfixable. These include psychopaths and child molesters. They do exist, though at a much lower level than the popular psychology industry would like to claim. They can't be fixed unless Gethin has some magic techniques that the rest of the world is totally unaware of, I am sure that his 'cure' will be as useless as any other method.
Isolation seems the only practical method.
Perhaps they may be fewer in a libertarian world, but they will still exist. First and foremost it should debunk the overblown statements of the institutions that make money and gain influence from the manufacture of false statistics. Secondly, it should link this particular issue to the numerous other ways that the social engineers terrorise the general population. This may make us few friends among what the 'left' has degenerated into, but tough luck. Thirdly, we should make it as uncomfortable as possible for the flakes in our own groups to justify and even laud any anti-social behaviour, sexual or otherwise.