The OP did not want to use beer traps or chemicals. I guess each of us has our own way of dealing with slugs...except that in the northwestern part of the US the slugs are humongous!! as are the snails. Yikes.
For me...I use a stick and pick up the black slugs, put them into a to-go cup, put the lid on and...forget to take it out of the sun. It's the best I can do.
Where I live we do have Rosy Wolf Snails and they like to snack on slugs, but if they don't eat fast enough, I have to step in and lend a hand.
