old1 asked "I want to try the ATF acetone mix. What is the mix ratio?" over a month ago.
It's 50:50 and needs to be shaken while working with it.
I mix it in an empty saline solution bottle for contact lens wearers because it has a flip top and a very small opening for control.
I leave my mix hanging on the wall in an old household spray cleaner bottle . It's been there 5 years now and still sprays fine.so I guess it doesn't eat plastic or it surely would have by now