I ought to tidy and clean more often- then I wouldn't have the problem...

On moving a sofa to clean under it, I found a big red wine stain on the stone floor beneath it. Probably spilt some ages ago, cleaned up what I could see, and missed the rest. And now it's well soaked in and oxidised to a brownish maroon.

It laughs at bleach. I've tried throwing salt on it over my left shoulder under a full moon at midnight, to no avail. There are legends about bloodstains that can't be cleaned up, but I can't remember killing anyone on that particular spot. The floor was supposed to be sealed, I obviously didn't check that well enough.

Any experience, suggestions, anything apart from giving up drink or floors or putting the sofa back and forgetting about it?