The breaking in ceremony is similar to an initiation or rite of passage, so to speak, and builds Esprit de Corps among Cav Troopers. In the days of the mounted cavalry, many hats were made with waterproof liners, not only to keep the rain off, but also to carry water. When a horse and rider would come to a steep riverbed, the Cav Trooper, knowing that his horse always comes first, would use his Stetson to scoop water for his horse to drink.
Cav soldiers have incorporated this practice into the ‘breaking in” tradition. The new inductee holds the hat upside down, and the senior spur holders pour a mix of different alcohols into the hat.