I plant about half my raised beds in white clover, and slugs can become a problem (especially here in the slug-rich Pacific Northwest!) I don't normally run my ducks there, but sometimes I will get some tongs and pick up slugs in the evening for the ducks. One good things about the cover is that slugs spend time eating that too, along with their favorite "decoy" plants like burdock, horseradish, and dandelion. When I didn't pisk
enough last year, I had some very large slugs taking out onion greens and few cabbages, but most things got on ok.
Nothing I've found has made this a big problem though - I'm keeping the living mulch!