How Did I Do (Not) Cleaning These Silver Coins And What Is That Green Stuff

I cant remember who it was or what thread it was in, but when I was searching about acetone, I remember someone mentioning contamination from storing coins in PVC and that it could be removed with acetone. I had a few coins which I though might have this problem, so I though I would give it a try. These coins were in soft clear flips. Is this PVC "damage"?
Before pictures:





For my (not) cleaning ("conserving?") I soaked them in water for several hours prior to acetone to see if that would do anything. It didn't. Then I put them in acetone and the color of the acetone the SLQ was in turned immediately a light green/yellow. I changed it out for fresh acetone and soaked for 4 hours.
After pictures:





What do you think? There is still a little gunk (possibly different that the green stuff) on the UN in UNUM that you can't see well in the picture. I might give it another acetone soak. or maybe toluene.

I have a 1926-D Peace dollar which has the same problem (same flip as the Morgan) that still has some original luster. I think I'm going to give it a go as well.

Please feel free to correct any of my terminology in this post