cocaine detection wipes pack of sachets - detect the presumptive presence of cocaine on any surface by swabbing the area with wipe turning blue upon contact with drugs (10) lupol limited a rapid presumptive method of determining the presence of cocaine residues, the swabs are foil packed for indefinite shelf life. simply wipe the test over any surface where you suspect the presence of cocaine, any traces present will produce an immediate blue coloration on the test swab. do not flush the wipe after using, dispose of in general household waste.