Step 1
Dust the entire wall with a duster to remove loose debris. Start at the top of the wall and work down.
Step 2
Fill a bucket with warm water. Fill another bucket with warm water and a squirt of liquid dishwashing soap, or mix a bleach-free all-purpose cleaner with warm water according to the labels instructions.
Step 3
Submerge a clean cloth in the cleaning solution and wring it out well.
Step 4
Scrub the wall in approximately 3-foot-square sections using the cloth and cleaning solution, working in a circular motion from the bottom up to prevent streaking. Rinse each section immediately after washing it with a clean rag and the clean water from the bucket. Dry each section promptly with another clean rag or towel.
Step 5
Repeat this process of washing, rinsing and drying the wall in small sections until the entire wall is clean. Move on to the next wall in the same fashion.