Whitewash is a cheap, watered down kind of paint. It was made famous here in Missouri by native son Mark Twain in the Adventures of Tom Sawyer. It has come to mean a kind of cover up, a veneer, a false face. It is a temporary covering to mask something that remains fundamentally unchanged. It looks and acts like paint, but it doesn't last.
Whitewash is a bit of paint mixed with a gallon of water.
For the first few weeks after painting a fence with whitewash, it can look clean and new. When the forces of weather and erosion began to blast away at it, the whitewash begins to quickly fade and it needs to be redone again. Quality paint costs much more than watered-down paint but it will weather the storms and elements. From physiology to ritualistic religion, we cosmetically change our behaviors to mask the depths of the wickedness in our hearts. We desperately seek to whitewash our sins and shortcomings in the hopes of appearing to be better men than we are.