Answered by Shaykh Faraz Rabbani
Question: I understand that when you go to urinate, you can clean yourself with a dry method (using tissue) and you can also use water. Is one method preferred over the other?
Answer: In the Name of Allah, Most Gracious, Most Merciful
The Messenger of Allah (Allah bless him and give him peace) said, “Ten matters are from upright natural disposition (fitra),” and he mentioned among them, “Washing away filth (istinja).” [Muslim and Tirmidhi]
It is reported that the Prophet (peace and blessings be upon him) cleaned himself with pure, dry stones. [Bukhari, Nasa’i, Abu Dawud, and Ibn Maja]
1. The sunna is to clean the private parts, such that no filth remains on them.
2. This highly emphasized confirmed sunna fulfilled by using any dry object that is pure, effective, and not of material value (such as toilet paper).
3. The sunna is also fulfilled by washing the area with water.
4. It is optimal to first use tissue paper or the like until one cleans the area, and to then wash it with water.
5. If one does only one, it is best to wash. The sunna is also fulfilled by merely wiping the place of exit using tissue paper.
6. If the filth goes beyond the place of exit and its immediately surrounding area, then one must wash. Wiping alone will not be enough.
7. One uses one’s left hand in cleaning one’s private parts. It is disliked to do so with the right hand.
8. It is obligatory to rid oneself of remaining urine before one starts wudu, as described in the answer below.
[al-Fatawa al-Hindiyya 1.48; Shurunbulali, Imdad al-Fattah, Sagharji, al-Taysir; Ayni, Umdat al-Qari Sharh Sahih al-Bukhari]