But the Nobel-prize-winning novelist has made them the subject of his latest novel, focusing on the sinking of a ship known as the German Titanic, which is rarely mentioned except in neo-Nazi propaganda.
The liner, the Wilhelm Gustloff, was sunk by a Russian submarine in 1945, as it carried 9,000 refugees and wounded soldiers out of Danzig (now Gdansk in Poland).
Authorised Hitler
"We, the expelled, may cry together," wrote a columnist in the Bild newspaper, Franz Joseph Wagner, who fled from the east with his mother.
"I thank you for this," he added, personally addressing Grass, who was himself born in Danzig.
Former Foreign Minister Hans-Dietrich Genscher wrote in his newspaper column: "Guenter Grass is writing not to settle scores, but to counter forgetting about the horrors and the distress always associated with the war."
Die Welt wrote in a front-page story: "In the likely bestseller, Grass has broken a historical taboo."
After the publication of the book, Im Krebsgang (Crabwise), on Tuesday, Grass, aged 74, went on to call for publication of Hitler's anti-semitic manifesto, Mein Kampf, in an interview for the weekly Die Woche on Thursday.
"One should always be allowed to read this madness," he said, saying that it should be published in an authorised edition with an accompanying commentary.
Neo-Nazi ban 'mistaken'
He called for basic information on National Socialism to be made available, and for public discussion of the phenomenon.
He said that would help young people who may be fascinated with Nazism, but do not understand the reality behind it.
He also criticised the German Government for trying to outlaw the neo-Nazi National Democratic Party (NPD), saying that German democracy was strong enough to cope with challenges from the far right.
He added that the ban was no protection against the populism of conservative leaders who "prepare the ground for the right-wing extremists".