Allah's Messenger said: "Do not perform Istinja, with dung, nor with bones. For indeed it is provisions for your brothers among the Jinn."
Jami` at-Tirmidhi Book 1, Hadith 18
← Previous Hadith "Allah's Messenger went out to relieve himself. So he said: 'Bring me tree stones.'" He said, "So I came with two stones and a piece of dung. So he took the two stones, and left the dung. He said: 'It is Riks (a degenerative or filthy thing)."

Jami` at-Tirmidhi Book 1, Hadith 17 Next Hadith → "Encourage your Husbands to clean themselves with water, for I am too shy of them, and Allah's Messenger would do that."

Jami` at-Tirmidhi Book 1, Hadith 19