Cleaning the wall after removing wallpaper can be a frustrating and messy job. Prepasted, strippable wallpapers and borders have a very strong, gooey adhesive that can be stubborn. It will take some time and effort to accomplish this, but it isn't a difficult job and requires few tools.
Mix and Spray
If you are using white vinegar you should mix 1/4 cup to 2 cups of warm water. Put this in a spray bottle and spray it on. Do only a small area at a time as you don't want the mixture and glue to re-dry. If you are using a commercial remover such as Dif, mix it according to package directions and spray on.
This is the difficult part. Use your scraper to go up the wall pressing down firmly to remove the adhesive that is stuck. This may be very thick and gooey. Dump the adhesive off the scraper into a trash can, don't let it fall to the floor as it will make walking very slippery and dangerous. Continue this scraping alternating with spraying until most of the adhesive is removed.
Wash the Wall
After you have removed as much adhesive as you can scrape off, scrub the wall with hot water and a strong household cleaner to remove any residue. You can tell spots you've missed as they will appear shiny on the wall. All adhesive must be removed or your next paint job won't be smooth and may not adhere properly.