I used the 3M Mildew Block spray and accidently got some on my glass. Seems strange, but the stuff dries very hard and I cannot seem to remove it from the glass. It leaves a milky spotty residue.
I have tried alcohol and finger nail polish remover that I think is mostly acetone. The alcohol did nothing, but the polish remover was slightly better. It is still way to difficult to remove.
If it's glass it won't scratch, if it's plastic use a brand new blade in the scraper and go slowly and start in an inconspicous place first to see if it's going to scratch.
Try Xylol. Much more potent. Soak a wrag with the stuff and let it set on the area for a while it should soften it. And yes if it's glass it will not scratch.
