If teenagers are already sexually active in this day and age due to the process of puberty and exposure to mainstream sexual propaganda, then it is only fitting that youth be taught how to properly manage the sexual energy.
The White Vajroli Mudra is the antithesis of masturbation. If you wish to help a teenager avoid the vices of masturbation, then the White Vajroli Mudra is the way.
Also, girls develop faster than men, around 18, whereas many young boys reach adulthood at 21. These age restrictions apply to beginning the practice of sexual magic. These are the ages when young couples can get married and begin working in the forge of the Cyclops. Before that point, young people should be taught how to transmute as single people when puberty sets in.
Sadly, kids are already fornicating at a young age, hence the necessity of educating them in the noble use of sexual energy (transmutation as singles) so that they when they mature, they know how to get married and practice in the right way.
For thirty years I sought God. But when I looked carefully I found that in reality God was the seeker and I the sought. -Bayazid al-Bastami