Old West saloon keepers were true whiskey 'alchemists', putting turpentine, gunpowder, kerosene, and ground red pepper into theirs. They also saved the 'leavings' from the bottles, by dumping them back into whiskey barrels.
The distillers also did that, and had their salesmen collect the empties from saloons, so they could dump the last drops into freshly distilled batches.
One such salesman was collecting the empties from Judge Roy Bean's old Langtry, Texas saloon, and was astounded that the bottles were bone-dry. The Judge told him: "The boys around here get so thirsty, they sop the insides out with their tongues!".