In a way similar to the “wash me” notes you can find on dirty cars, it is about scrubbing or cleaning the dirt off the surface to make a creative statement. You don’t make any damage to the walls or cars, so it is relatively ‘harmless’ comparing to other forms of street art. There are no toxic materials used — only soap and cleaning tools. But still, the artists sometimes get arrested by the police because it is still considered to be graffiti.
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