Pour 1 gallon of hot water in a medium-sized bucket.
Add 1 cup of non-sudsy ammonia, 1/4 cup of borax and 1/4 cup white distilled vinegar. Stir until the borax is dissolved.
Test an inconspicuous area of your wall by sponging a small amount of the homemade cleaning liquid over it. It should be fine, but if it causes any discoloration at all do not use it.
Wipe down the walls. Dip a sponge into the cleaning mixture and start wiping downward from the top of the wall near the ceiling. Re-wet the sponge as necessary.
Dry the walls immediately after washing with a lint-free towel. Setting a few fans in the room will also help speed up the drying process.