I tried dropping lily beetles in jars with water (in my garden in Norway), but after a while I found it was more humane to kill them right away, squashing them with my fingers. Do you know if these beetles are a nuisance here in the south as well?
I also used to be sqeamish about killing snails and slugs, they have become a terrible nuisance in Oslo lately, much worse than before and especially this year, and I used to put them in jars with salt, but I now feel it is less barbarian to kill them right away, using the heel of my shoe. Those watching me may not think so when they see me doing this stepping dance in the garden, but it does help.
I am actually surprised to see there are so few pests here in my garden in Greece, except a few aphids, which are easily checked with a hard spray of water and my fingers, I don't think I have seen many other bugs, no caterpillars yet, but we do have olive fruit flies.