I've just washed it in my regular laundry detergent in the washer. If you've tried all you've listed (I would have given up long ago), you might want to try some diluted bleach with detergent in a washing machine load as a last ditch effort before you toss it. The bleach really brightens old fabric and removes any odors. The fabric might not last 500 years because you exposed it to a bit of bleach, but it will not smell.