Personally speaking, I would punish sex offenders (rapists, molesters, pedophiles, lust murderers) with methods that would make the Roman and Spanish Inquisitions look like a bunch of squeamish old ladies: by skinning them, force-feeding them their hacked-off penises, tying them up with piano strings and leaving them to a hungry rat pack... something like that. Alas, four hundred centuries have deprived the world of the few positive aspects of our old-school legal system.
Nowadays we're into scientific methods that may or may not work. They don't, more often than not. Among such methods is the one described in this book, which seems to be no exception to the rule.
Cognitive-behavioral therapy is supposed to change one's behavioral patterns by changing one's thought patterns. Some see it as a threat to human dignity, since it's basically a medical and legal attempt to reshape a human being from within. Others have focused on the actual results of such technique(s), which are at the very least questionable when it comes to either be condemned on the basis of a quack's clumsy report or get away with any sort of abomination courtesy of that very same quack's 'thorough analysis'.
In short, psychology, psychiatry, psychoanalysis, psychotherapy and CBT have proved themselves unable to deal with raging beasts who aren't in the least concerned about the moral consequences of their crimes, but only with being locked up - and therefore prevented from doing it again. That's the problem when you can't get it up unless someone ends up in a hospital bed or in therapy. Extreme deviance isn't compatible with social life, but the deviant has his own priorities: if he does heal from his mental illness, games are over. The Cat in the Hat must pack up and leave.
No doubt it's interesting to see how these Clockwork Orange methods were (still are?) implemented in a few American institutions: penile transducers, pupillometers, polygraphs, measurements, endless verbalisation of violent fantasies to the point of boredom etc. But I wonder whether it's really worth bothering (and wasting the taxpayers'money) when only 0,0001% of the subjects are genuinely willing to give up on their one and only source of pleasure.