The Germans themselves were aware of the stories , as SS-chief Heinrich Himmler had received a letter describing the Poles ' belief that Jewish people were being `` boiled into soap '' and which said that the Poles feared they would also be used to make soap . The Germans themselves were aware of the stories , as SS-chief Heinrich Himmler had received a letter describing the Polish peopleÂ s belief that Jewish people were being `` boiled into soap '' and which indicated that the Poles feared they would suffer a similar fate .