Cleaning, stains and fabric ID? on 30s 40s knit dress w/ metallic trim

Hi all,

What is the best way to clean this and possibly remove the grime / discoloration around the neck and upper back area? It looks not that bad in photos, but really needs a clean. The fabric just feels kinda grimy. How should I deal with the metallic trim? It seems to be one piece that has been tucked and sewn up at the appropriate places.

I tested it and it burned until the tip of the tweezers.

Will post another post about dating it. =)