In Brume Tower, after the foyer bonfire, I was helping somebody as a phantom and I saw a hole in the wall after the first fume sorcerer that wasn't there in my world.

My research seems to indicate that the only way to open this hole is by exploding a barrel-carrier near it. But all my barrel-carriers are dead beyond their respawning limits.

Can anyone confirm if there is any/no other way to open this hole? Am I wasting my time trying to get the big demon guy to break it open with his hammer?