cotton shot
n.— «A cotton shot consists of the heroin and blood residues that are “pounded” out of a cotton remnant (sometimes an old cigarette filter) which was used in a previous injecting session to filter the heroin solution as it was drawn into each individual injector’s syringe.…Those members with more successful income-generating strategies categorically refuse to “pound cottons” and they often humiliate those who are regularly reduced to seeking cotton shots.» —“Participant Observation Study of Indirect Paraphernalia Sharing/HIV Risk in a Network of Heroin Injectors” by Philippe Bourgois, Charles Pearson National Institute on Drug Abuse (Bethesda, Maryland) Feb. 1, 2005. (source: Double-Tongued Dictionary)