The solitary analogue to The Shocker.
Ennis: I pulled the Shocker last night.
Jack: Two in the Pink, one in the Stink?
Ennis: No, the Self Shocker. Two 'round the Pole, three in the Hole.
Accidently plunging your finger/fingers into anus,once and not enjoying it, during the act of wiping. Usually because of inadequate wiping material. Doing this repeatedly falls under self gratification.
That toiletpaper is so thin I just got a self shocker.