Keep in mind that when using any compound on your guitar and even your car, you are not removing the scratch but bringing the rest of the finish down to the level of the scratch by removing the finish. Repeated applications can burn the paint, meaning you start to see through the paint to the primer or bare wood, depending on how the finish was applied. If this is a daily player or gigging guitar, I would suggest leaving it alone. You will have more scratches within a week. If you are getting ready to sell the guitar or put it in a museum, I would then consider restoring the finish.