I say, and with God's success: The water that a person in a state of ritual impurity uses for ablution becomes used water, and it becomes pure but not purifying for the ritual impurity. It is permissible to remove real impurity from clothing and the body with it, but it is not permissible to perform ablution or bathing with it; because the water becomes used as soon as it is used to remove the ritual impurity, whether it is with the intention of removing the impurity or without any intention at all. Refer to: Sharh Al-Waqaya p. 99, Al-Hidaya 1: 20, Noor Al-Iidah p. 23, and Al-Sayah 1: 396-397, and God knows best.