I have tried almost everything - beer traps, copper rings, eggshells, organic anti slug granules, nematodes. We have song thrushes in our garden although no hodgepigs recently.
Absolutely nothing seems to stop them stripping our dwarf beans. I've seen them marching forth over copper rings and the stuff that is supposed to stop them dead in their tracks. Nematodes made absolutely no difference and cost a lot of money to treat a small bed.
I just grow things that slugs don't like these days and leave the rest, or grow it indoors!