A bag used to hold the contents of an alcohol enema. It is used in conjunction with a joose nozzle. Alternatively, a Fleet enema can be used in place of the joose-bag.
The bag is filled with an alcoholic drink, most commonly the brand Joose, thus the term joosing.
The bag must be air-tight and (re)sealable, as during the joosing process, it is put under considerable pressure due to the forcing of the Joose into the rectum of the recipient.
Shit, Nismo! Whatchu buyin' them cheap-ass joose-bags fo? You know they only good for one joosin', and my butt needs more bubbly!