Yeah here's hoping it's really thick vinyl so there's enough of a layer that isn't damaged, otherwise it's all for naught. Acid softens vinyl--some of the people who used the "slug method" to try lowering T/A found this out--you can SEE the vinyl wrinkling where the acid is destroying it.

Swimming in that? You might end up skinny-dipping when it dissolves your suits...depending on your POV this could be a bad thing , or a good thing !

I hate to be pessimistic, but I think this liner, if it's not toast, will have a much shorter life.

But, as Richard said, you are doing everything right.