Simple weathering

[faraway]

I forgot to mention that the water based wash is made with detergent. But sometimes is the surface just to perfect. A better method would be to apply a layer of dull coat to get a better grip.
The tricky think is that alcohol based wash worked several time as expected. An Athearn CR GP15-1 got a nice fade effect combined with the following water based black wash. This one went pretty well too.