I used Mini Slug Pellets or MPS when I was a commercial grower, they are blue, I had free ranging ducks and geese and cats, animals did NOT eat these. I lived in a good climate then but it did rain slugs. I got them from Wilber Ellis, Wilco and Cenex may have them also. The big box/home gardening stores will NOT have any. It comes in 50# bags and no - that is not too much for me and my tiny yard. (However, it is way too much for my crippled body)
I will have to get more since I am the only one gardening in this hellhole and all the slugs (and !@#$%* squirrels) come to my yard. Also the neighbors tree roots.