Keep the suggestions coming. Looks like we can all learn some tricks. For example, I was sure that perfume was a lost cause.
I have had more success than I expected with my husband's clever idea of blasting the garment with our ozone generating device. We got this device twenty years ago for killing mold spores, and use it primarily for that purpose. We've moved house a lot, and every place seems to have its moldy corner.
Anyway, apparently he is really onto something. I did a very cursory reading, and it turns out that using ozone to clean garments seems to be getting popular with professions dry cleaners:
https://americandrycleaner.com.....e-garments
I'm at maybe 85% improved in less than 24 hours. Nonetheless, that last 15% can be pesky. I'll give it some consideration. I have to try out several other dresses which are currently on order, and see what makes sense for me.