White Vinegar Stains

Hi

How do I remove a large white vinegar stain from a carpet?

There is some backstory. I used some white vinegar to clean my fitted lounge carpet, and subsequently used salt to remove the vinegar from the carpet. Unfortunately - and after using copious amounts of salt in the process - the carpet is still slightly damp with the white vinegar. Worse still, it has now left a dark metre square stain in the carpet itself. The question is: how can I save the carpet?

PS. Am I correct in thinking that white vinegar is supposed to remove carpet stains, not create them?