Quoted from Pin_Fandango:

resurrecting this thread...
Located in Canada and can't find naphtha here... Would ZIPPO lighter fluid be a good replacement?

Quoted from Nokoro:

Definitely wax. Every 500 games or so.

Quoted from homegameroom:

Don’t forget to replace the pinballs as well. They get little micro scratches and can damage the playfield as well.
I live in a humid climate, so I replace mine twice a year. You should be able to see a difference in the new balls versus the old ones.

Quoted from DakotaMike:

I disagree. I think wiping down the playfield, and replacing the pinballs regularly, is all that's needed on these newer Sterns. I suspect that most wear on modern playfields comes from rough and scratched balls. And from my experience, there are major downsides to waxing modern games.
My old 1980 Black Knight was great with wax, played fast, but not too fast. But my new Sterns are awful after waxing. Even some of my B/W games like Johnny Mnenomic or Mousin' Around are scary fast with wax. I've literally chipped plastics on those games after waxing, to the point where I had to clean the wax off. I left it on some high-wear areas like shooter-lane exits and top rollovers, but that's it. The ball was out-of-control fast, and was breaking plastics and chipping standup targets.
Right now, I'm operating under the precept that the pf clear coats on newer Sterns are robust enough that it's not worth the downsides of waxing. As long as I clean the pf regularly with say Naptha, and make sure the balls are in good shape, then that should be sufficient. I think that older, slower playing, non-clear coated games, can use the protection and speed boost of wax, but not new stuff. Also, I question how long the wax barrier can hold up to a fast-rolling pinball on a games like Stranger Things or Dead Pool, especially once multiball kicks in. My suspicion is that owners inspecting and replacing the pinballs, and cleaning their playfields, which owners do during the waxing process, is actually what's protecting their games long term. Not the actual wax itself.
And like I've said all ready, my problem with the carnuba wax is that the games play way too fast to the point of being out-of-control and to the point of breaking plastics. Not worth it to me on modern games. But to each their own.