Hoppe's Boresnake Viper - 20 Gauge
Hoppe's Boresnake is the fastest bore cleaner on the planet. One pass loosens large particles, scrubs out the remaining residue with a bronze brush, then swabs it all spotless with a cleaning area 160x larger than a standard patch. The brass weight on the end of the pull cord has the caliber of the Boresnake stamped on it, so you always know which Boresnake you're using. Just add Hoppe's No. 9 Cleaner and Oil or Boresnake CLP to the head and tail of the Boresnake and run it through your bore for a quick clean.