"Yes its completely true.
I had a buddy just come back from Afganastan (again) and he says that they can't understand why we use paper to wipe. They think that you can't possibly get clean enough that way.
All of them wipe with their LEFT hand and eat with their RIGHT. Criminals get their LEFT hand cut off as a punishment. That way EVERYBODY knows that he wipes his butt with the same hand that he eats with."