Has anyone had success with airing? How long did it take? I bought a futon innerspring mattress for my son this past week. He slept on it the first night and said it was comfortable but if we close his bedroom door the smell is horrible. At first I thought it was spilled tea...that's what it smelled like...sour tea. I thought it was the cover but after removing it to wash it the room still smells and we haven't put it back on yet.