Very dangerous. Campden alone won't work. If you use both Campden and sorbate together, it might keep for a little while, but even then will begin to ferment and gush or explode over time. The only way to kill everything dead is to pasteurize, the same way that you would do canning like making jam or whatever, bottle it then heat it up in a big kettle of hot water to like 170 F for 30 minutes to kill all organisms. This *should* work although I myself haven't tried it with beverages, only jam.