I thought that the חכם צבי was Rov of the קהיךות אה”ו Altona Hamburg Wurzburg, which are in west Germany
Grandpa Zushy [not the rebbe R’ zusha, his gggs and my ggf] grew up near Lemberg, and he related that they once brought an African guy to advertise shoe polish. Many people made a brocho משנה הבריות but Grandpa was convinced it was just shoe polish and didn’t. Only later in life did he realize that it was for real.