I work in a high volume restaurant. Recently we obtained a red wine barrel that has been used ounce. It has been empty for about 6 months. We want to use it to cask age a pre mixed cocktail. We are planning on filling the entire thing with a mixture of spirits (no juices etc, all alcohol over 40%). Should we use a sulfur stick to sterilize it or will the high alcohol content sterilize the oak cask and all of the nooks and crannies? We plan on leaving the mix of spirits in the barrel for about a month.