When I started buying 45's as a 12 year old, I wrote my name on them all, so when we had dance parties I would know which were mine. Don't have them any more, but someone else may, and is wondering who I am ;-).
The UK type glossy jackets are not a problem---they can be cleaned with liquid. It's our U.S. paper ones that don't appreciate getting wet. I've used Bestine (found at art supply stores) for years to remove price sticker glue residue, which if applied very sparingly does no harm. Slaw, where did "the Sleeve City guy" make his recommendation, and what was it? What is the name brand? I agree, bacteria on LPs and their jackets is not something I care for!