As someone said, if you got poop on your arm, maybe while changing a diaper, would you wipe it off with a piece of paper and consider it clean? No, not if you're from the mainstream of any developed country. You would use water, soap, and maybe more extreme measures.
Well, why do you leave your anus caked with residual poop, then? Advance into the 18th century: get a bidet, and learn to use it. Overcome your ignorance and embarrassment. Even I did.
(I still use toilet paper in public restrooms, though. They usually don't have bidets.)