I have been using the Westland Advanced 'ferric' pellets for many years and they have worked very well.
But, they have become harder to find last few years and have become quite expensive, so I have moved over to Doff ferric pellets and they have been just as effective.
The important thing is to follow the instructions, 5g per square metre. Weigh it out your first time and you will be amazed how few you need to spread about.
So often, I see people spread loads about, almost like in clumps. That is when I would worry about any pets or wildlife.
Of course, as well as pellets;
Well worth trying beer or I use a home bread yeast mixture traps around the plot (yogurt pot inside another, so easy to lift out and top up and they have the perfect fitting lid).
Th traps work well for me and always find after a night of heavy rain I have traps containing plenty of slugs and snails.
A torch light brigade late evening, especially after it has rained to pick them off, especially your paths.
Cooper tape under the ring of all your pots I have found to be effective too. Never found a slug or snail in any of my pots. Mind it is important also for pots to sit t on a hard base like concrete or a gravel mix over some weed control to stop slugs coming in from the bottom of the pot draining holes.
Finding and saving slugs and snails is also a good idea, as you can save them and make a nematode bucket, which I have done for about a decade now.
Spread over my new potato raised beds and over the soil underneath the new and maincrop potato bags and not had any sign of a nibble from a slug.
Do also water some into the veg plots, before planting.
Nematodes do not stop snails, as they do their work underground.
Can't say any year including this one has been any different, you will always get slugs and snails, but you can certainly keep them under control, with regular visits and techniques.
Also, get to know your slugs, as some are actually good for the compost heap or mulching and do not eat/harm your produce.
The Green and Yellow cellar slug do not eat plants, they are mulch eaters and good for your compost heaps.
Leopard slugs are also good as they are also mulchers plus attack slugs, they do not eat your produce.