and wind! lol.
yes have tried nemaslug, we took over our plot from an old couple who hadnt been able to tend to it for years, the slugs were in slug heaven, tasty veg self seeding everywhere and lots of weeds, thanks to some help from other grapes on the vine (our wedding present) the weeds are under control, the nema slug really helped with the slugs we tried the organic wildlife safe granuels which worked till it rained then they just came back and ate everything, we tried beer traps but that seemed to increase the slugs (they can smell beer for a few hundred meters so they came from all around.)you have to do the whole patch a few times a year but if you have raised beds and use copper tape it will help, it works on the babies and the keel slugs underground too and has really reduced the population.
also we could still feed them to our chooks after we'd used it. I dont think we will ever be free from them but they are much less in number and more manageble now, we dont even mind them that much anymore. If you slug population was as bad as ours I'd say nema slug every time.

__________________
Yo an' Bob
Walk lightly on the earth
take only what you need
give all you can
and your produce will be bountifull