Yesterday I wrote about the shine that builds up because of "dirt" and oils. Now remember if you clean your jeans regurlary, without washing, which is possible, the "dirt" is nothing to worry about. Even the daily sweat, can dry over night, if you hang your jeans up at night in a cool dry place. Don't fold them up, as that is when they will start to smell. And believe me, that's gross.
The jeans above are my first pair of Harris jeans before and after its first wash. You can clearly see the difference between.