Invocations:

Invocation for entering the restroom

"[بِسْمِ اللهِ] اللَّهُمَّ إِنِّي أَعُوذُ بِكَ مِنَ الْخُبُْثِ وَالْخَبَائِثِ".

10. [Bismillaahi] Allaahumma 'innee 'a'oothu bika minal-khubthi walkhabaa'ith.

(Before entering) [In the Name of Allah] . (Then) O Allah , I seek protection in You from the male and female unclean spirits.

Reference: Al-Bukhari 1/45, Muslim 1/283. The addition of Bismillah at its beginning was reported by Said bin Mansur. See Fathul-Bari 1/244

Invocation for leaving the restroom (bathroom/toilet)

"غُفْرَانَكَ".

11. Ghufraanaka

I seek Your forgiveness.

Reference: Abu Dawud, Ibn Majah and At-Tirmithi. An-Nasa'i recorded it in 'Amalul-Yawm wal-Laylah. Also see the checking of Ibn Al-Qayyim's Zadul-Ma'ad, 2/387.