I say, and with Allah's success: It is disliked to use the right hand for cleaning oneself, except in cases of necessity; as narrated from Abu Qatadah Al-Ansari , who reported: "When one of you drinks, let him not breathe into the vessel, and when he goes to the restroom, let him not touch his private parts with his right hand, nor wipe himself with his right hand," in Sahih Bukhari 1/69, 5/2133, and Sahih Muslim 1/225. This is because the left hand is for impurities. Refer to: Al-Badai 1: 19, and Allah knows best.