How to get the smell of damp out of chiffon material?

[Ce111]

I bought a quite expensive dress for a wedding I went to last year. Since then it’s been left in a damp room (a huge mistake I know) and now the smell of damp is really bad on it. Does anyone have any recommendations of how I can get the smell out as I want to wear it again for another wedding in 2 weeks? Or should I just cut my losses and throw the dress away? It’s a chiffon material.

Hang it outside as much as you can.
Try spraying a bit of Febreze on a bit you won't see if it does mark it.
What does the care label say? Can you hand wash it?

This is what the label says - doesn’t mention hand washing x

Put it in the washing machine. Or I guess you've already tried that.

Have you tried washing it or dry cleaning it?

I would put it on the hand-wash setting through the washing machine with plenty of powder and then line dry it.

What is the actual fabric content?