Wash supposed to dry??? No, that's why its called a wash. Its wet.
You mix a bit of black acrylic into some window cleaner or windshield washer fluid. Make sure its mixed well and then take a paper towel or sponge and soak some of it up, then take and rub it over the piece. Be sure to have a dry towel handy to wipe off the extra drips. Do this lightly until you're comfortable with the dirty appearance that starts to appear. The purpose of the window cleaner over water is that it drys a lot faster due to the alcohol evaporating.