Chris writes:

So what is the prep/remover for floor polish?

Typical ingredients for an acrylic polish stripper are butyl cleaner,
ethanolamine, benzyl alcohol, coupler/hydrotrope(s). Sometimes an alkali
like NaOH or KOH or ammonia. Think of it as a harsh but water-based paint
stripper (think of the acrylic polish as acrylic paint without pigment), or
oven cleaner. Related to 409 or Fantastik type household cleaners

Here's an example:

http://www.betco.com/MSDS/184.pdf

PoliPrep is more or less a dilute subset of that. Plus a pretty blue dye.