Millswax is solvent based. It has a pretty healthy dose of petroleum in it. Just smell it!
Drop a few year old bottle of mills wax on the concrete and see what happens - the stuff actually eats the bottle from the inside!
On a pre-diamondplate machine, these petroleum based products are actually recommended many times by the manufacturer. Will you eat through your playfield? Highly doubtful. But, it will soften plastic posts and other plastic parts.
Wildcat and millswax are pretty potent and useful on the older games.. but don't put them on diamondplate!