Well, I have some suggestions to try - not looking forward to it because I don't want to make a bigger stain than what's there. The weather here in Oregon has been in the mid-high 90's the past week or so and expected to continue. I'll have to tackle this in the early morning hours.
1) getting someone else to do it would be an option - if I could.
2) the eye glass cleaner was a light blue similar to Windex but not as dark. Yes, it's sorta soapy........
I'll try Oxyclean first.....
I'll post the results.........when I have something, good or bad.