Yes. Potassium sorbate stops the yeast from replicating, and k-meta kills wild yeast. I add both to my wine and still mead. Rumor says 1 day is good enough, but I always use it and allow 3 days before I backsweeten wine or mead. If you're talking about beer, let it finish fermenting on its own. Don't stop the process in beer unless you want a sweet weak beer.