A very strange omission

This illustration (from a French bande dessinée, the title of which is unknown to me) depicts Gilles de Rais burning multiple bodies in a large fireplace, exactly as described in the trial. This is, if not impossible, then at least highly improbable. The temperatures required to incinerate a human corpse are very high indeed - crematoriums take one and a half hours to incinerate an adult corpse at temperatures of 1600-1800°C. By comparison, a house fire would usually reach 1200°C and casualties would not be burnt to ashes. Even a large fireplace in a castle could not hope to achieve these temperatures. And then there is the stench - not just of burning flesh, but also of hair, nails, blood, wet internal organs, the content of the gut. Given the length of time it would take to reduce a body even to a skeleton, and the number of alleged victims, this would have been almost a full-time activity. Yet, although there had been a "public rumour" that Gilles de Rais murdered children, nobody at the trial commented on any foul smell or dense smoke around his castles. And that seems a very strange omission.