Getting outside/walking can be good but there's still a lot of activity hitting your senses. People, cars, animals, sounds, or all of the above. If you can find a quiet park bench to sit and sort of defocus it might work. But more than just taking a break, when you "stare at a wall" you are engaging in deliberate sensory deprivation, which might be a better reset for your analytical mind. All that said, if taking a walk works for you, great!