I believe he used the Holy Razor of Atra. It was a communal razor used by many friars of the time. Each brother was to sharpen the razor after they used it. However, many of the brothers didn't like doing this dull job, so they'd skip sharpening the blade, assuming that the next brother to use the Holy Razor wouldn't notice. Unfortunately, this didn't work as eventually no one sharpened the Holy Razor. This resulted in many a scared face. Friar William noticed that the newest brother, Brother Braun of Saxony, was hardly ever called away. Therefore he assigned him to be the official razor sharpener. The simple solution worked and nary a scared face was seen again throughout the order.