This page is on the Sally Hansen website. They are giving tips for "Rescuing old polish" by putting nail polish remover in bottles that have gotten thick. This is a BAD, BAD IDEA! Putting acetone in nail polish permanently ruins it. That's why we use it to take nail polish off. That's why they make nail polish thinner, which is like $4 at Sally's Beauty Supply (not related to SH).
Is this a ploy to make you buy more Sally Hansen nail polish? Is it like magazines telling you that nail polish expires after a year? *ahem* Nail polish does not expire, like ever... true story! Or is Sally Hansen, and company that's been around for 60 years, really that ignorant? What do you think?