Interesting ideas. I suppose depending on how sick the fish is, scooping it out and quickly finishing the job with a hammer MIGHT be easier/faster than overdosing it with clove oil. Though I think if the fish was still swimming around and has enough energy to fight being captured, attempting to net it would take longer, and most likely be more stressful for both parties. IMO, If the fish was just laying at the bottom, simply picking it up and killing it would be humane and overall painless if done correctly. Nevertheless, I am very thankful it was not my decision to make, and my goldfish decided it was time.