If you don't have clove oil, vodka is the next best thing--or any other type of strong liquor. Freezing is another way, but flushing will not kill your fish immediately. He would continue suffering, except it would be in the hell of your septic lines.
It is not true that fish cannot feel pain. Anesthesia is required on the use of fish when doing surgical procedures for scientific experiments. Pain is an evolutionary development to aid in survival, and to suggest that fish cannot feel pain is ridiculous.
It is not true that fish cannot feel pain. Anesthesia is required on the use of fish when doing surgical procedures for scientific experiments. Pain is an evolutionary development to aid in survival, and to suggest that fish cannot feel pain is ridiculous.