If the wall is still standing still after a few bangs it’s time to move onto another wall. For it’s still a wall and might just have a softer spot. I would also recommend using a different device then the one above to break it. Too much time can be spent on a project that isn’t moving and all your getting is a headache by now. So continue to seek the goal but go at it from a different direction and then the cracks might just appear in ways that don’t hurt your head anymore.