Is “She was executed and buried with her face covered by hair and mouth stuffed with bran” true?

The Records of the Three Kingdoms, Book of Wei, Biographies of Empresses and Consorts, Pei's annotations, citing the Book of Wei, records that Empress Zhen, having lost favor, uttered complaints and was ordered by Cao Pi to die; her funeral was treated harshly. The original text: 「汉晋春秋曰：初，甄后之诛，由郭后之宠，及殡，令被发覆面，以糠塞口，遂立郭后，使养明帝。」(Source: Book of Wei, Biographies of Empresses and Consorts.txt)