The challenge with pavers is how the sand/soil between pavers captures weed seeds. The least invasive way to manage the weeds is hand or tool removal. There is no evidence that vinegar and water will manage weeds and grass. As you mention, chemical treatment is another option. There are some organic products that may work. Of note, once you have eliminated the weeds and grass there is a sealing treatment, that can be done professionally, that will reduce the sprouting of weed seeds between your pavers.