I say, and with God's help: The leftover water from the sarsar is pure and its use is not disliked; due to its lack of impurity, there is no dislike in it, except if it is in a place that is impure, in which case it is disliked. Refer to: Maraqi al-Falah 32, Al-Sayah 1: 465, and Radd al-Muhtar 1: 149, and God knows best.