He increasingly associated with old Nazis living in Chile as well as with their neo-Nazi sympathisers. In May 1984 he attended the funeral of Walter Rauff—a member of the Waffen SS who had played a role in organising the early stages of the Holocaust and who had fled to Chile after the Second World War—and there gave the Nazi salute. In 1986 he published a political manifesto for Nazism in the Southern Cone of South America. He began organising annual celebrations of Hitler's birthday at a rural retreat in Chile. In September 1993, he led a neo-Nazi rally in Santiago—dressed in what had become his trademark black leather coat—in honor of the Nazi Rudolf Hess and the Nacistas killed following their 1938 coup attempt. As well as playing a role in organising the Chilean neo-Nazi movement, Serrano maintained correspondences with neo-Nazis elsewhere in the world, such as the American Matt Koehl.