If it helps I was just shopping at Chanel in NY yesterday and asked them the same question. They said you don't need to store it in the box but they recommend you take your flap or any bag, pulling the chain inside, wrapping it with tissue and stuffing (so bag keeps its shape), if part of the chain lays on the very top, insert tissue underneath it as well as under the flap, then putting it in its dustbag and storing it right side up. They said it will prevent it from denting or loosing its shape. They also told me to not condition the bag with anything, only use the natural oils from your fingers, that is if its lambskin. Hope that helps!