[hueving]

>What did I miss? OP is arguing that we should wash our behinds for the same reason that we wash our hands.

No. OP is not arguing that. OP is arguing that if you got mud on your hand and tried to clean it with dry paper, there will still be crusted mud on your hand. Do you see where this is going now?

[baddox]

OP simply doesn't say that. OP refers to the actual common act of washing hands after using the toilet, not the hypothetical act of washing hands after getting "mud" on them.