That’s an interesting method to be sure. I was wondering how the glue would be removed after it dried. 8>)
If the album covers and sleeves were under water, they are ruined. They aren’t worth anything, unless they are albums that you can’t find any copies of.
Should just peel off, I saw YouTube videos on it several years back, not sure if it works?
I think a very light cleaner like used to wash vegetables may be best, nothing abrasive or with heavy chemicals,