How to get a label off often depends on whose label it is. Breweries will use different types of glue. New Glarus bottles are the easiest to remove the labels from with just a day long soak in water. Pilsner Urquell labels come off with a soak in hot water, and then peel. Most paper labels will come off, or be softened enough to scrape off, with a soak in a weak PBW solution for a day to three days. I use a 2 inch plastic dry wall mud applicator for the scraping.