From Orderly and Humane: The Expulsion of the Germans after the Second World War, by R. M. Douglas (Yale U. Press, 2012), Kindle p. 280:
In each of the expelling countries, governments, residents, and ecclesiastical authorities struggled mightily to eradicate all indications that Germans had ever been present. As Edvard Beneš urged his compatriots, “We must de-Germanize our republic … names, regions, towns, customs—everything that can possibly be de-Germanized must go.” Place names were changed overnight, often by direct translation into the new language (e.g., the substitution of “Zielona Góra” for “Grünberg”); statues and memorials demolished; and fanciful local histories composed that airbrushed into oblivion centuries of German presence. “In Wrocław the government had special teams that roved for years painting over and chiseling out German inscriptions. Derelict German cemeteries were converted into parks, and headstones were used to line ditches and sewers.” The most ambitious—and unrealistic—attempt to accomplish this objective was an order by Commandant Srević of the Banat military region in Yugoslavia that all German signs on buildings be removed within twelve hours, on pain of the immediate execution of the German occupants. Nor was this a passing phase. As late as 1989, applications for visitors’ visas to Poland from Germans born in the Recovered Territories were routinely rejected if the applicant used the former German place name when stating his or her place of birth. The de-Germanization effort extended not only to penalizing the use of the German language, but to putting pressure on residents to abandon German-sounding personal names. The success of the campaign, however, was mixed. Cultural and sometimes physical clashes ensued between settler Poles and many of the indigenes of the Recovered Territories, who had absorbed over the years a high degree of Germanization. New place names could also be rejected by the local population, who sometimes “boycotted new names and even broke road signs that identified the new name…. For them, place name changes on the lands in which they had been living were never the processes of re-Polonisation, but rather Polonisation against their will.”
Consigning evidence of German settlements to George Orwell’s “memory hole” was one thing; putting self-sustaining communities in their place entirely another.