When I have excess sexual energy that I need to dissipate I focus on the energy in my pelvis, and I concentrate it there and pull it up through my stomach and to my heart. One can continue to pull it up to the voice and up into the mind. This sexual energy can be redirected to other focuses. This is a good temporary action. However, your friend cannot just keep pushing his issues with sex out of the way. He will need to examine his relationship with sex directly and work through complexes he has there. It is virtually impossible not to have sexual complexes, so this would be good work for anybody really.
Iron Pentacle work is one possible way to work through complexes: http://www.reclaimingquarterly.org/67/pentacle.html