Chemical strippers, opposed to sanding or heat-stripping methods, do the least amount of damage to the surface of the drywall. Choose to use chemical strippers if you are removing paint from drywall that has irregular surfaces. This includes drywall that is scratched or chipped. The chemicals will get into the nooks of the irregular surface and will remove the paint. Be aware that chemical strippers are harsh and can pollute your home's air environment. Air out the house several days after using the stripper to ensure that smelling the fumes does not cause damage. Always wear rubber gloves, goggles and dust mask when working with chemical strippers.
Heat gun stripping does not utilize harsh chemicals and is preferable to chemical stripping if you are removing paint from drywall inside the home, and you will be living in the home while you work. Heat guns are also preferable for flat surfaces. Heat guns apply heat to the drywall. Be careful not to apply too much heat as you can start a fire. Keep a fire extinguisher handy in case the drywall heats up too much and starts a fire.
Stripping paint from drywall by sanding it will take longer than the chemical and heat gun-stripping methods. But this method allows for the most control and does not use any harsh chemicals. Unlike the other methods, this method also will smooth out the drywall. Drywall sand is fine and will move to other parts of your home easier. Avoid this by closing doors and putting a cloth at the bottom of the door. Open the windows to ventilate the room.