Ok so you guys want to mock because I said there are actually instructions on the proper use of clove oil?
Yes a high dose of clove oil does kill a fish but it is a shocking death. The fish literally acts as if is is burning all over( probably burns its gills).
A measured out dose and the fish does go to sleep, then you administer the fatal overdose and it feels nothing. I did a lot of research including reading first hand experiences from people who did it incorrectly and saw the fish freak out painfully before death.
For those interested here is just one of the links to use clove oil in a humane way:
http://www.oscarfishlover.com/helpful-articles/euthanize-fish
The other method that is actually quick and supposed to be humane is the cutting off of the spinal column to the brain. Yep in simple terms cut the head off.