Dust the wall first with a dry microfiber cloth or vacuum brush attachment
Mix a small amount of mild dish soap with warm water
Dampen a soft sponge or microfiber cloth in the solution
Wring the cloth out well so it is barely damp
Test on a hidden spot before cleaning the whole wall
Gently blot or wipe the stain without scrubbing
Work in small sections from top to bottom
Use a second clean damp cloth with plain water to remove soap residue
Dry the area immediately with a soft towel
For stubborn marks, use a baking soda paste very lightly and test first
Avoid abrasive pads, harsh cleaners, and excessive water
Repaint touched-up areas if cleaning dulls or removes the finish