yes some places use a hose which goes to the bottom, others dont. i used to work a growler station and we didnt use a hose. we just poured beer straight from the tap into the growler then closed it up. in a screwtop growler, if unopened can stay carbonated for anywhere up to a month or so. a swing top could stay carbed even longer. however, once either of them are opened you really want to try to drink as much as possible so you dont waste any. i opened one swing top for 2 beers, and closed it up, stuck it in my fridge, less that 12 hours later i opened up for another and it was flat. so the key is, when you open one make sure you get out as much as possible.