Using vinegar to clean carpet is extremely common...and unfortunately extremely unhelpful (in most cases). The explanation is really pretty simple, but very interesting: most spots on carpet are acidic, and vinegar is an acid, so by using vinegar you can actually set stains into the carpet. When we are cleaning, one of the purposes is to neutralize the pH value of what we are cleaning. That is why we almost always start with pre-spray that is on the alkaline side of the pH scale, which goes from 0-14. From 0-6 is acid, and 8-14 is alkaline, with 7 being neutral. So if the average spot is say, a 4, we would want to use an alkaline that is 10 so that it goes back to a neutral 7.
Vinegar is often a 2 or 3 on the pH scale, meaning you would only use it to counteract a fairly strong alkaline. In most cases, the spot you are trying to clean on your carpet with vinegar is an acid, so you are just adding an acid to an acid, making it harder to get out later.
Instead, use our free spot cleaner (neutral pH), and if that doesn't work we can always stop by to take care of the spot!