I put nemaslug on my garden last year and it saw off all the slugs, I was so pleased that I have again put it on this year, just last week, and yes, it does kill snails too although when I spoke to the supplier they are not allowed to advertise it as such. I agree, stabbing them seems rather cruel. Alternatively, get a jam jar, a quarter fill with beer, (drink the rest), and the next morning empty the dead slugs out of it, replacing the beer. Do be aware that foxes love the beer though, I have several visit me each night, 2 are hand fed, although they scatter if anyone else goes near them.... but they dig up the jars for the beer.
