I say, and with God's success: The leftover water from the was'ah is disliked to use for purification as a matter of preference when there is other water available that is not disliked. It is not disliked in the absence of pure water; due to the necessity of its circling, it resides in houses, unlike the scorpion, the beetle, and the cricket; due to their lack of impurity, there is no dislike in them. See: Maraqi al-Falah 32, Al-Sayah 1: 465, and Radd al-Muhtar 1: 149, and God knows best.