How do I kill my goldfish quickly and painlessly?

[KringleCandleLover]

I have a goldfish which has been swimming upside down for a few weeks.

Tried different methods to correct this but he has gone from bad to worse. His gills are going like the clappers and he's at the bottom of the tank.

He's had no food for over 24 hrs.

How do I put him out of his misery? (Serious question).

DH says we should flush him down the loo, DM says just put him in the bin..

I can't do it. I want him to go quickly and not suffer..

So I have 5 goldfish and four of them are eating the fins of the fifth and I have tried all methods of stopping it, including changing out the water, feeding them a considerable amount more food, etc. but it continues to happen and unfortunately the fifth one is having too much trouble swimming and I want to help stop it from suffering I might try the clove oil.