I haven't used any sprays etc in the rest of my garden for years( years ago was always spraying my roses against this, that and the other) but have never been able to give up using slug pellets on hostas and lettuces which I grow in pots. Other things they devoured I just don't grow any more eg delphiniums, ligularia, marigolds, clematis. On clay soil which doesn't help.
I have hedgehogs and thrushes in the garden but they don't make a bit of difference to the slug and snail population. I've tried copper tape, WD40, eggshells etc on the pots but they still eat them, the only successful thing is a few of the blue pellets.