The Messenger of Allah (ﷺ) forbade the use of bone or the droppings of camels for wiping (after excretion).
Sahih Muslim Book 2, Hadith 75
← Previous Hadith I see that your friend even teaches you about the excrement. He replied; Yes, he has in fact forbidden us that anyone amongst us should cleanse himself with his right hand, or face the Qibla. He has forbidden the use of dung or bone for it, and he has also instructed us not to use less than three pebbles (for this purpose).

Sahih Muslim Book 2, Hadith 74 Next Hadith → The Apostle of Allah (ﷺ) said: Whenever you go to the desert, neither turn your face nor turn your back towards the Qibla while answering the call of nature, but face towards the east or the west. Abu Ayyub said: When we came to Syria we found that the latrines already built there were facing towards the Qibla. We turned our faces away from them and begged forgiveness of the Lord. He said: Yes.

Sahih Muslim Book 2, Hadith 76