Submerge a rag or sponge in water. Squeeze out the water until the sponge or rag is barely damp. Gently rub the glue to soften it. Turn the rag to use an unused portion and continue rubbing the glue until it comes off the wallpaper surface. Dry the wallpaper with a soft rag.
Fill a bucket or plastic container with warm water. Add a squirt of dish soap and gently stir the water. Dip a sponge in the water and wring out the excess soapy water. Rub the glue marks with the sponge. Rinse the sponge in the bucket and wring out the excess soapy water. Rub the glue marks again until the stains disappear from the wallpaper.
Mix equal amounts of white vinegar and water in a bucket. Dip the corner of a soft, white rag into the mixture. Rub the stains softly to make the glue sticky. Wipe the stain with a dry, white rag. Dip a new section of the rag into the white vinegar and water, and rub the stain again. Alternate between rubbing the stain with vinegar and water and then immediately drying the area until no glue stains remain.