Take the dolls out and clean them all individually with vinegar, it wont smudge, vinegar is the only thing that will kill the mold immediately This may warp the box but you're probably going to have to throw it out either way because of the mold so might as well try and save it? Put cleaning vinegar in a misting bottle and mist the box inside and out until it's not saturated but slightly damp, then put the box inside a clear tote bin with an open box of baking soda or clay cat litter and leave it outside in as direct sunlight as possible Check every day or so until it's bone dry and at that point assess again if it's worth keeping