I would just like to report that I have had enormous success killing slugs
with beer in SW Ohio. Stroh's and plastic cups are all that are required.
I caught seven - yes seven - slugs in one night with day-old beer. Dumping
seven soggy dead slugs from a plastic cup was both nausiating and rewarding.
I think so far I've killed about two dozen 3-4" adult slugs this year,
mostly with beer but also by smashing those that I happen to see when I'm
out at dusk or dawn. Plus I've probably killed about half a dozen baby
slugs when they've been tracked into my house by the dog and cat. If it
weren't for the babies getting into the house, I probably wouldn't be half
as determined to kill the breeders.

But I am wondering (since I was asked) if slugs serve any purpose in a
garden. I've only seem them eating my flowering plants, which signed their
death warrants.