So, I had bought this a little over 4 months ago. I have used it off and on, but have never really mentioned it. It is Beauty Secrets Nail Polish Thinner. I have saved quite a few of my old/crusty nail polishes. They arent really old, but have dried up, grown crusty or too thick to paint evenly. I just pop in 2-3 drops of this thinner, turn the bottle upside down, roll between my hands. And woila..!! Magic. Nice and creamy nail polish that paints evenly.
Yet, you can also use nail polish remover without acetone, or acetone. however, I find when I use those they dry up after a while. However, I also still use them when I am in a time crunch.
This bottle is less than $6, found at Sally's Beauty Supply and lasts a longgggg time and can be used over and over, and in every brand of polish. A definite must have if you collect polish like me :)