Quoted from BLACK_ROSE:

A Must Read about Millwax from ( The CEO ) of Millwax .. I'm Sure he's eYe-ball-n Pinside now.
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Hello Mark,
Please forgive me for the delay in responding to your inquiry, it came at a time when I was in the process of negotiating all the myriad details of the sale of the plastic injection molding portion of my business and arranging to move numerous large (one a multi-ton) pieces of equipment out of our shop, as well as dealing with my mother's serious injuries, and then trying to find an empty nursing home bed for her while she recovers fully. It has been a trying couple of weeks. I appreciate your understanding.
Thank you for contacting me with your concerns about Mill Wax. Let me begin by telling you that I have been collecting pinballs for somewhere around 23 years now, hundreds of different games over the years. In that time there probably isn't a playfield cleaning technique or product that I haven't tried, and I still find Mill Wax to be my preferred product of choice. Obviously I am a little biased, as the owner of the company, but it ultimately comes down to performance and Mill Wax gets the job done right, quickly and easily.
Based on what you read on the internet, you seemed fearful that you had ruined your playfield; buying in to the hysteria promulgated primarily by one man who seems to have developed a real hatred for our product and has taken it upon himself to bad mouth Mill Wax at every opportunity. While I can appreciate this individual's contributions to the pinball world and his love of the hobby, his continual disparaging comments and attempts to mislead the pinball community about Mill Wax really needs to stop.
It really all comes down to a matter of personal preference. Some people like a lot of salt on their food, some a little, and some none at all. I generally prefer a lot of salt, but I harbor no ill will towards those with a different preference. I personally own and drive a Ford, but I haven't made it my life's work to bad mouth Chevys, Dodges or any other vehicle; it's simply a matter of preference. I get great results using Mill Wax to clean my playfields, it has made my life a lot easier, and I feel good knowing that I have taken the necessary steps to protect my valuable investments. That's why I bought the company, and that’s why I personally use it on every machine I own.
Tens of thousands of satisfied customers agree, using Mill Wax to clean and protect games of every vintage, from the earliest pin and ball games, to the very latest Stern titles. People prefer Mill Wax over other products because it works, but not everyone agrees. It is unfortunate that a few individuals have taken to try and destroy the reputation of a great product like Mill Wax. If they have a problem with our product, they should contact me directly, or simply use the product they prefer, although I must caution you, I see a lot of strange ideas about playfield maintenance on the internet. As for myself, I will stick with a proven performer like Mill Wax.
Mill Wax has been on the market since 1976, and continues to be the number one choice for both the restoration and routine maintenance of pinball playfields. Used properly, it does a fantastic job of cleaning dirt, carbon, grunge and rubber ring debris from the playfield and laying down a protective coating that helps prevent wear and preserve the graphics. And by the way, this additional piece of advice: don't forget to spend a few bucks and replace the ball(s) from time to time, a rusty, pitted ball will quickly wear out a pinball playfield in a way that no brand of product can protect against.
Yes, Mill Wax does contain a silicon component, and that can be a problem for someone seeking to clear coat their playfield, IF, they haven't properly cleaned and prepared the surface. To make an extreme analogy, you wouldn't prep your car for painting by simply taking a broom to it and sweeping off the dirt. I'm no auto body man, but I do know that there are numerous cleaning, sanding , wiping steps necessary to meticulously prepare a car for painting, which take a lot of time to properly perform in order to get the best results.
The preparation of a pinball playfield is much the same, requiring it to be rigorously cleaned and prepared, no matter what type of wax or cleaning product was used on it in the past. Even a new machine, straight from the factory without any playfield product ever having been used, requires careful preparation and cleaning prior to clear coating. Like most things in life, if you take the time to do good work and carefully prepare, you will get good results, and having used Mill Wax on a playfield is no obstacle to getting those good results if one takes the time to properly clean and prepare the surface in accordance with the clear coat manufacturer's instructions. You may wish to consult with the clear coat manufacturer for specifics about their products and how to get the best results.
I sincerely hope that you won't let the fear mongering and flames of a few on the internet outweigh the positive results of tens of thousands of satisfied Mill Wax customers around the world. You can continue to use Mill Wax with the confidence that you are protecting and preserving your investment in your pinball.
Thank you very much,
John F. Buegel, Pres
Mill Amusement, LLC

Quoted from cfh:

let me repeat this...
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Novus2 is Paintable. that means you can paint on a surface, without problems, after you have used Novus2. Millwax is *not* paintable due to silicone. That's the issue as I see it. Because once Millwax is on a playfield, you have to jump through hoops to get a clearcoat to stick to that playfield.
The other issue i have with Millwax is the name, which implies it has wax. There is NO wax in Millwax, just silicone and (basically) Novus2 combined, using a really smelly pet dist solvent (which irritates my hands), and installed in a bottle that likes to crack and explode. Since the name "Millwax" implies something it is not, on that fact alone, i refuse to use the product. Add to that the difficulty in doing a clearcoat in the future on a Millwax'ed playfield, and i think there's *much* better approaches to cleaning a playfield.
Also if i want to "wax" my playfield, i would indeed want to use a wax, not silicone. Silicone gives NO benefits that wax does. All it does is "slime" the surface, essentially like a really sticky oil. Wax does not work like that - it fills the microscopic flaws in the playfield, making for a more level and smooth surface. This helps deter wear. Having "oil" on a playfield doesn't do that. Hence it's better to use Novus2 for the polishing, and then either stop or wax with a genuine wax.
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To add to that, silicone is *extremely* difficult to get off a playfield once applied. I do clearcoating. I do a lot of clear coats. And i swear up and down everything i get a game with an old bottle of Millwax inside. Because frankly i can't get all the silicone off! Instead I have to use a very generous amout of "Smoothie" to get a good finish.
So what is Smoothie? It's silicone! Basically i have to add silicone to my clearcoat, in a greater amount than is currently on the playfield, to get a smooth (non fish-eye) finish. This of course screws the next guy down the line that has to do another clearcoat (if ever needed again.)
I will also add this - do not trust Steve Young for accurate information in regards to playfield cleaning. First, Steve hasn't operated a game since the 1970s. Second, Steve has never clear coated a playfield. Third Steve doesn't own a game newer than 1980. And fourth, Steve is financially involved with Millwax (hence his reason to push the product.) Generally Steve is right on with information on anything pinball. But when it comes to Millwax, he's just plain wrong. (He didn't even know the product didn't contain wax, but had silicone! I had to inform him of this fact.)