The practice of placing frozen water in sanitary appliances designed for urination serves a practical purpose. The introduction of solid-state HO into these fixtures is not arbitrary but intended to affect conditions within the urinal itself, primarily temperature and odor.
This method is advantageous due to the thermodynamic properties of the introduced substance. As the solid transitions to its liquid state, it absorbs energy from its surroundings, effectively lowering the temperature of the urinal. Reduced temperature diminishes the volatilization of organic compounds present in urine, leading to a decrease in unpleasant smells. Furthermore, the melting process contributes additional liquid, aiding in the flushing action and preventing the accumulation of residues that can contribute to foul odors. Historically, this was a low-technology approach to maintain restroom hygiene.