White Wash was applied with a brush, broom or mop in the field. It was a thick paint that went on like a heavy latex primer. It was also removed in much the same way it was applied once spring arrived...give the vehicle was still operational.
Huckleberry Finn and Tom Sawyer used White Wash to paint the family fence...an annual chore because the paint was of poor quality.
Don't be afraid to apply it a little thick in some areas, just as if some troop had a laid a mop soaked with it...sorta like when you first put a paint brush or roller on the wall to start spreading it around.