Well, Milos may be a great prep, but he wasn't a brilliant competitor as he use everything and didn't make epic progress like others of his day. Compare him with Nasser and his transformation, or Ronnie, Flex, Kevin, Dorian ... Yes, all these guys used GH, slin, SEO, diuretics ... but Milos seemed like a natural swimmer next to them.
Maybe his genetics didn't allow him to respond to drugs and his diet and training (special and advanced) metods, maybe he competed too much and didn't have an off season to grow ... whatever it was, if he wasn't a guru, Milos would not be remembered for any show look or any spectacular results during his career.
So, Milos used all available resources (putting his life at risk) to get mediocre results. There are hundreds of pro bodybuilders with not perfect genetics who did the same as Milos, but added size, condition and toughness to their bodies throughout their careers.