I say, and with God's success: The hen that roams in filth, so one does not know the purity of its beak from its impurity, it is disliked to use its leftover water for purification as a matter of preference when there is something else that is not disliked. It is not disliked in the absence of pure water; because it is pure, and it is not permissible to resort to dry ablution (tayammum) in its presence. As for the hen that is kept in a house and fed, its leftover water is not disliked; because it does not find the droppings of others to roam in, and it does not roam in its own droppings, but rather it notices the grains among them. Refer to: Maraqi al-Falah 32, Al-Sayah 1: 465, and Radd al-Muhtar 1: 149, and God knows best.