When my DP takes the dog out into the garden last thing at night, they go with a torch and several dog poo bags. He usually collects 2 or 3 bags full of slugs and snails and he just seals them up and puts them in the bin. We seem to have mainly big black slugs up here in Yorkshire, I've not seen many green ones.
I don't favour the salt method as it leaves bodies and, although the dog has stopped eating absolutely everything it sees now it's turned 1 year old, I believe slugs are still quite dangerous to dogs.
What I don't understand is that I have a pot full of dahlias flowering without a problem, but the one spare dahlia I popped in a another pot of cannas next to it, has been shredded. I'm leaving it as a sacrifice to the great slug god at the moment.