Yes, they do. They do state that purchasing anesthesia is the best, but I do not have the money or resources for purchasing that.
Here are a couple websites out of the many that suggest freezing:
How to Humanly Euthanize Your Fish - Rate My Fish Tank
"Freezing is a commonly used method for euthanizing warm water fish. To freeze your fish, freeze water in a small bag until the ice is slushy. Then place your fish in the water and continue to freeze it. The folks at Web Web Media advocate using the freezer but other people feel that this method must be somewhat discomforting to the fish. Out of all the "old-school" methods, this process seems most humane. The AVMA does not advocate freezing fish as an acceptable method of euthanasia; the only way they would approve of cooling would be to deep freeze an animal already under deep anesthesia."
Aquarium Fish Euthanasia
"Ice-Cold Bath
Tropical fish less than 2 inches in length can be euthanized by exposing them to freezing cold water. The fish is put into a small container along with some aquarium water at the normal temperature. This container is then placed into a much larger container filled with crushed ice. This will rapidly chill the water in the smaller container, eventually rendering the fish unconscious. When death is verified, the fish can be removed."
Your suggestion is even more gruesome than I imagined, and is even outlawed in some states:
"Decapitation
While too grisly for most aquarists, stunning a fish, decapitating it and then pithing it (physically destroying the brain with a metal rod) is a humane way to euthanize a fish. Because fish can remain conscious for some time after decapitation, the pithing step is essential. If you don’t know how to pith a fish, then don’t use this method."
Q: Humanely Euthanize Beta? - Pet Care Experts Answer!
A: The best way
The best way to humanely euthanize a fish is by putting it in a plastic bag and putting it in the freezer. Make sure you don't wrap the fish in a towel, napkin, ext. because it can keep your fish alove longer by keeping a little bit more warn and moist. Before euthanizing a fish be sure there is nothing left you can do to help the fish. The fish should be dead in about 5 mins in the freezer.
Here are a couple websites out of the many that suggest freezing:
How to Humanly Euthanize Your Fish - Rate My Fish Tank
"Freezing is a commonly used method for euthanizing warm water fish. To freeze your fish, freeze water in a small bag until the ice is slushy. Then place your fish in the water and continue to freeze it. The folks at Web Web Media advocate using the freezer but other people feel that this method must be somewhat discomforting to the fish. Out of all the "old-school" methods, this process seems most humane. The AVMA does not advocate freezing fish as an acceptable method of euthanasia; the only way they would approve of cooling would be to deep freeze an animal already under deep anesthesia."
Aquarium Fish Euthanasia
"Ice-Cold Bath
Tropical fish less than 2 inches in length can be euthanized by exposing them to freezing cold water. The fish is put into a small container along with some aquarium water at the normal temperature. This container is then placed into a much larger container filled with crushed ice. This will rapidly chill the water in the smaller container, eventually rendering the fish unconscious. When death is verified, the fish can be removed."
Your suggestion is even more gruesome than I imagined, and is even outlawed in some states:
"Decapitation
While too grisly for most aquarists, stunning a fish, decapitating it and then pithing it (physically destroying the brain with a metal rod) is a humane way to euthanize a fish. Because fish can remain conscious for some time after decapitation, the pithing step is essential. If you don’t know how to pith a fish, then don’t use this method."
Q: Humanely Euthanize Beta? - Pet Care Experts Answer!
A: The best way
The best way to humanely euthanize a fish is by putting it in a plastic bag and putting it in the freezer. Make sure you don't wrap the fish in a towel, napkin, ext. because it can keep your fish alove longer by keeping a little bit more warn and moist. Before euthanizing a fish be sure there is nothing left you can do to help the fish. The fish should be dead in about 5 mins in the freezer.