Move any furnishings from the wall containing the wallpaper with excess paste. Place the furnishings in another area or on an opposite wall. Place a dropcloth or piece of plastic sheeting on the floor under the excess paste.
Wipe the wallpaper with a soft, non-abrasive cloth or rag to remove loose dust and dirt from the surface.
Place a paper towel over the excess paste. Spray the paper towel with glass cleaner or a 16-oz. spray bottle filled with one cup of white vinegar. Do not let the glass cleaner or vinegar run down the wall--this will stain your wallpaper. Let the glass cleaner or vinegar sit for 10 minutes.
Peel the paper towel from the wallpaper slowly, then blot the excess paste with the damp towel.
Repeat steps 3 and 4 until the excess paste is gone. Let the wallpaper air-dry or aim a box fan toward the wet wall.