What are you using to clean LP album covers?

Two things stand out from your post: You store your records in a environmentally controlled residence via HVAC, hence you have control of mold. Secondly, you have encountered mold on used records where you had no knowledge or control of the environment. We could expand the scope of the discussion. People living in cool damp climates are more vulnerable to mold than people who live in arid or semi-arid climates. I am comfortable with that. Not using record covers is still a safer option, but the world is not black and white. What is important here is to provide an exchange of information so readers can make informed decisions. BTW, my house in Florida is under HVAC 12 months a year. I probably wouldn’t have a mold problem unless we had a prolonged power outage such as after a major hurricane. We only have those increasingly frequently. Why worry? Records would be the least of the problems facing an intrepid audiophile after a catastrophic event.  What's a little mold?  Besides we can always sell 'em on Discogs.

I use a magic eraser on anything glossy and just a slightly damp microfiber for matte finish.  I only do it on thrift store finds for the most part, while in many cases the vinyl appears/sounds unplayed, the records have obviously been stored in less-than-archival envinronments.

If I have to remove a price sticker, I use a hair dryer to loosen the adhesive. Remove the LP first! I use baby oil to clean and polish, then leave it out for a couple of days before putting in an outer sleeve.