I would lay them outside in the grass for a couple of days. If that doesn't work get one of the boxes of baking soda that is made for the refrigerator and seal them up in a bag with it for a week or so. Martha Stuart say to put things in a bag with some crumpled newspaper for a week or so. I have never tried it.
I would think this should at least make it so you can stand the smell to sew them. Ironing might bring back some smell but hopefully it will be much less. Then you can wash the whole thing when it is finished.