Rubbing alcohol solutions are compounds that contain skin moisturizers. I don’t know what components are integral to after-shave products, but I have no doubt they leave a residue. The lens may have acquired a coating. Always clean with 100 percent pure isopropyl alcohol (gently).
I use Plexus for taking out very light scratches on CDs. (I am given to understand the Air Force uses it on the windshields of stealth bombers.) This might also be of help in bringing the lens’ focusing back.
If it is not a coating problem, then I would assume that the lens assembly is out of alignment.