There's a wide range of different products I looked at online.
Everyone talks about best ways to clean carts but not how to preserve the contacts over a long period of time.
I also wonder if an effective product was found if it wouldn't also help make a good connection when playing
like some rough carts I've owned, no matter how polished those contacts are, the game wont work unless you blow on it.
When we were kids people would also lick the contacts. I assume the moisture was helping to make a better connection
I've worked with di-electric grease before, I worked in a factory assembling truck cargo bodies (wiring lights, back up cameras, etc)
So the idea has popped into my head a few times.