The Case of a Well and Things that May Fall in It (Fatwa best explains Ahadith 2-12 as well as the following chapter.)

10. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad from ibn Mahbub from ibn Ri’ab from Zurarah who has said the following: “I once asked abu ‘Abd Allah, Alayhi al-Salam, about a rope made of the hairs of hogs which is used to take out water from the well. Can Wudu’ be made with such water? He (the Imam) said, ‘It is not harmful.’”