Retro Game Maintenance

I was wondering if you guys wanted to share your methods for maintaining your retro game collection. I didn't keep up with my cartridges at all until a few years ago, at which point I started using the rubbing alcohol and Q-tip method of cleaning the contacts. But I think there might be too much corrosion from old age and from me blowing on them as a kid. I've been looking at the products on this site, but I'm wondering if I should save my money and find some other solution:

https://www.nintendorepairshop.com/products/81--1-Nintendo-Game-Cleaning-Kit/

If I can get some of the really messed up ones working again, I'm going to try and install some new save batteries since most of them have died out by now. Anyway, if you guys have thoughts you wanna share, go ahead and post!

Ars Technica recently posted a feature that seems relevant to this. Take a look, maybe it can give you some good advice.

https://arstechnica.com/gaming/2013/08/the-cheap-easy-way-to-make-those-old-game-cartridges-as-good-as-new/