Summarize this article:

After time is up and you have spot cleaned the wall, spray the wall with water. Start spraying at the top and move downwards. Make sure to remove all of the detergent. Go over the wall several times to ensure that the detergent is all gone. You may want to focus on a small area at a time rather than spraying the wall all over.

Summary:
Rinse the detergent and dirt off of the wall.