We found that the natural solutions didn't have quite the effect as the store bought snail bait. I use one with iron chelate as it's meant to 'improve' the soil as well.
I have small pieces of black PVC pipe nailed to the garden edging. I put the snail bait in this. It's big enough for the snail (or slaters were our big problem) to get in, but dogs and cats can't get it (nailed down so that the dog didn't just play with it). It was a bit of an effort to start with, but worth it for me in the long run.
I have heard that egg shells are great, as well as other gritty things that hurt the snail.
Try the ABC Gardening Australia website too. They have ideas/fact sheets for all gardening issues.