This is an ongoing concern with old Featherweight cases and some are worse than others depending on where they have been stored. All sorts of remedies have been tried- activated charcoal, kitty littler, dryer sheets, Febreeze, sunshine. I used the Absorb compound that we always had on hand at school in case someone was sick. I washed it out well with bleach, Sunlight dish soap and vinegar and then put a container of the Absorb in there for a week and closed it up. Then I put it out on the deck in the strong sunshine for several days. It's now much better but I keep a bar of Irish Spring soap in it at all times. This seems to take care of the smell problem.