ive used the garbage disposal. but im a sick man lol. it was the easiest way i could think of. i didnt have to see it and it was cleaned up for me. just run the water first if you decide to do it. otherwise it makes a nasty sound.
Haven't we done this thread before, very recently? I think o.p. could do a search on here and find lots of answers on the last persons thread about this subject. Good Luck with your fish in the future.
I euthanize most of my fish by feeding them to bigger fish. It's the natural way for the fish to go, and gives another fish a gourmet meal.
At work when a fish needs to be euthanized (from sickness) I just slam it on the floor. Hands down it is the quickest way for the fish to go and they are dead 100% of the time the instant they touch the ground. If a fish is swollen I do that in a bag to avoid a mess (and it does happen if the fish is retaining water/infection in it's swimbladder).
I think it is more stressful to throw the fish in a new environment for a couple of minutes waiting for the clove oil to kick in. Fish suffer immense stress from a change in habitat (even if the water is from the tank, the new tank/bucket are clearly different to the eye). It literally takes 2 seconds to grab the fish from the tank and slam it on the floor though.
Feed it to a larger fish your keeping if not sick, I have done this with tiger barbs to my bichirs...
The only other time I had to euthanize a sick silver dollar that was barely alive but breathing, unable to swim or even right itself, into a net then into the outdoor pond...80* down to ~45* if the shock didn't kill it, the cold water def. did...