I've not heard of the brand but I use a similar product. Citric acid added to 20%+ acidity vinegar is a potent herbicide. You have to be careful where you apply it as it will "creep" beyond your applied area.
Something to consider also is the affect it has on the soil. From what I understand, the citric acid works as a contact while the vinegar is taken up by the roots and messes with the plants ability to take up water. As you mentioned, it's non-selective. Once everything you wanted killed has "assumed room temperature", you will have to correct the soil pH with calcium prior to planting anything else in the same location.