Not only is this book promoting homophobia, against human rights and ignoring the WHO policy, but also scientifically impossible according to the American Psychological Association:
"In many of these behavior-change techniques, "success" has been defined as suppression of homoerotic response or mere display of physiological ability to engage in heterosexual intercourse. Neither outcome is the same as adopting the complex set of attractions and feelings that constitute sexual orientation.
Many interventions aimed at changing sexual orientation have succeeded only in reducing or eliminating homosexual behavior rather than in creating or increasing heterosexual attractions. They have, in effect, deprived individuals of their capacity for sexual response to others. These "therapies" have often exposed their victims to electric shocks or nausea-producing drugs while showing them pictures of same-sex nudes (such techniques appear to be less common today than in the past).
Another problem in many published reports of "successful" conversion therapies is that the participants' initial sexual orientation was never adequately assessed. Many bisexuals have been mislabeled as homosexuals with the consequence that the "successes" reported for the conversions actually have occurred among bisexuals who were highly motivated to adopt a heterosexual behavior pattern."
[...] Then again the people that promote this book must prefer living in the Middle Ages than in the 21st century.