Best I've seen so far is a 1/2 Litre bottle at 30%, enough for 6 Litres/1.585 US Gallons !
Might have to go that route, when I need to strip acrylic from a model.
I've found something in a Home Bargains store (in the UK) called "Wizz Bathroom Cleaner", a green liquid with less than 1% Ammonia, good enough to shift year-old Vallejo crud from a mixing palette, & general cleanup, inc bathrooms, but it won't shift my fave paint mix as below.
Mr Muscle Kitchen (orange bottle in the UK) has a similar ingredients, but I haven't tested it.
I don't use windex/windolene as a thinner or cleaner for acrylic paint. though
I use Medea airbruush cleaner to errr clean my a/b,
& Vallejo Polyurethane Primer + cut with Future/Klear (old formula) as a primer, tough as boots.