Dirty Bag

A dirty bag is marijuana-smoking device - an alternative name for a lung... generally a 2 litre soft drinks bottle with the bottom cut off, and a bread bag sellotaped around the bottom. Burning the marijuana on a foil gauze on top of the bottle whilst drawing the bag downwards causes smoke to collect in the bottle and bag. You then remove the gauze and suck the contents. Multiple useage causes a brown residue to collect inside the device - hence 'dirty bag'. In some semi-rural communities, disparate groups of dope smokers have been known to share a dirty bag, which is stashed in a particular bush or under a bridge for communal usage by whoever is passing by.