I had to do it.
Hello there, I am a new poster. And what a thread on which to make my first post. But this topic is what made me come onto the site in the first place.
For years I have been "fish-sitting" a grandson's Betta when the family goes on vacation. Two months ago when I went to get the fish they told me he was sick. So I brought him to my house and began reading online to try to figure out what was wrong with him. As it turns out, at age 6, he had several tumors on his body, one of them a huge one located in front of an eye. All he did was lay on his side at the top of the bowl.
I got the medication recommended, changed his water every other day, and felt I did all I could. I "nursed" him for a month. (Grandson was long home but I told him fishy was too sick to come home, took him out to Petco and we got a new fish for him. He was happy.)
Finally, despite all the care, Polly would not eat. At all.
I used the alcohol method. I dumped about an inch of rubbing alcohol (which you can buy very cheaply at any drugstore) into a small plastic Tupperware type plastic container. Then scooped fish out of his bowl into a small plastic cup of water. Drained most of the water out of that and then gently dumped fishy into the alcohol. It was very quick and I hope painless.
I will confess that it took me three days after realizing this was going to be necessary to actually do it.
In the meanwhile, on that day at Petco with my grandson while getting him a new Betta, I saw a beautiful red Betta with a Delta tail and got it for myself! Yayyy! A first time Betta owner I became!
A week later I was at Walmart to purchase some supplies. Oh.my.gosh! I was very upset about what I saw there! I immediately rescued another red Betta (a crown tail type with some fin problems and a tumor under it's mouth) that was in about 3" of dirty water in a small plastic cup. So now I have the two, in separate bowls.
I also promptly emailed Walmart Corporate Headquarters and complained about the fish treatment and the condition of the fish tanks at that store. The store manager called me the next day and "promised to make sure the tanks are taken care of better in the future".