"Your companion (meaning, the Prophet(ﷺ)) even teaches you how to go to the toilet!" He said: "Yes, he forbade us from facing the Qiblah when defecating or urinating, or cleaning ourselves with out right hands, or to use less than three stones."
Sunan an-Nasa'i Book 1, Hadith 41
← Previous Hadith "I am like a father teaching you. When any one of you goes to Al-Khala' (the toilet), let him not face toward the Qiblah nor turn his back toward it, and let him not clean himself with his right hand." And he used to tell them to use three stones, and he forbade using dung or old bones.

Sunan an-Nasa'i Book 1, Hadith 40 Next Hadith → "The Prophet (ﷺ) wanted to defecate, and he told me to bring him three stones. I found two stones and looked for a third, but I could not find any, so I picked up a piece of dung and brought them to the Prophet (ﷺ). He took the two stones and three away the dung and said: "This is Riks."

Abu 'Abdur-Rahman (An-Nasai') said: Riks is the food of the jinn.

Sunan an-Nasa'i Book 1, Hadith 42