I don't mind sharing at all. Pardon my detailed account. I believe your compassion for your fish deserves to know every detail.
I read the "Sticky" here on this site, regarding the various euthanizing methods and the relative "humane" approach each method yields. I also spoke with many people, including a friend who is a DVM, and people at my local fish stores.
The method we choice was adding "Clove Oil" to water, and immersing her into that solution. After leaving her in that bath/solution for about 15 minutes, we removed her lifeless body and placed it in a zip-lock baggie, and put her in our freezer for 48 hours. The 15 minutes and 48 hours was to be absolutely certain she wouldn't reanimate IN CASE she was in a deep suspended animation state — a state similar to hibernation.
Given that goldfish are in the carp family, carp have been known to survive in near-frozen water. So, all of the "dip her in near-frozen water" methods were discounted; immediately off the table as a viable means. Other methods were too brutal, barbaric and/or methods I just couldn't do.
The Clove Oil method was fast. Based purely on observing her last "visual" life signs (breathing, eye movement, fin movement) she was gone within 4.5-5 seconds of immersion. It was literally that quick. When I placed her into that bowl, she showed no signs of panic or being alarmed. It was literally 4-5 seconds of ordinary breathing — then she was gone.
The Clove Oil can be found at GNC, about $9 for a small 2 oz. bottle.
1. I placed one tablespoon of the oil into about 0.8 gallons of her rehab tank water, so the temperature was the same as what she was used to.
2. I stirred the water vigorously, such that the water becomes a bit cloudy white (as if I had poured milk into the water).
We each had a moment to touch her, say our goodbyes and a quick prayer to our little family member —
3. using my hand, I lifted her out of the rehab tank and quite quickly placed her into the bowl of oil-treated water.
The clove oil — at that dosage — is an extremely potent numbing agent. She might have experienced the equivalent of being extremely sleepy and "light-headed". She would have felt no pain.
It took me a few weeks to come to this decision. After literally trying to rehab her for months — with no success — and living with the inevitable conclusion, I thought it best for me to be the person who ends her suffering.
We were sad for the following days; this is to be expected. Afterwards, however, I was relieved she was no longer suffering. I was quite surprised with how much stress I was carrying over this fish's condition and lack of quality of life. Clearly she wasn't going to recover; it was the best and only thing to do.
Please contact me if there is anything else I can do to help, any further questions you may need answered. Best to you and yours —