I believe the product SLUGGO (1% iron phosphate) is available in the UK, if
that's where you live. It's very effective and won't hurt animals. I got
some a week ago because slugs devastate our strawberries. I saw results by
the next day, and now we enjoy the fruits of our labor (pun intended). It's
a lot less expensive than nematodes, and can be stored indefinitely until
used.