My dad continued having kids until he was about 65, and personally, surgery never appealed to me, and I doubt that it appeals much to the 18 to 25 single men set.
However I think it's going to be extremely difficult to find a compound which guarantees that not a single viable sperm will be produced while not doing any appreciable amount of temporary or permanent damage to the user.
To this laymen that seems several orders of magnitude more difficult than preventing the implantation of a single fertilized egg in the uterus.
L