I griow around 65 different hostas in pots, and have done for around 15 years. I nearly gave up around 6 years ago, the slug and snail problems being virtually overwhelming. I tried it all, hair, egg shells, garlic, porrige oats etc. et. ad nauseaum. Then I discovered copper tape, now each pot has its own collar of copper, and that has done the trick. I have a three tiered display, like a very large auricular theratre, and the edges of that are also trimmed with copper tape. There will always be the odd clever slug that walks up the wall and drops into the pots, but on the whole the collectiion is doing very well. I also bury odd bits of copper tubing (from a friendly plumber) around the stems of plants that are devoured by slugs, e.g delphiniums, and that has helped enormously tool. Apparently they get a small static shock from the copper and will not cross it. It was quite expensive to do at first because I had to do the whole lot at once, but now just as any new pot arrives. Do try it, it really does work.
Ferrous pellets work somewhat, but are very dangerous for children, as an overdose of iron can be lethal. They do not harm birds and other mammals as far as I know. Use them very sparingly and where they cannot be seen by small people. The other kind should be abolished at once I agree. We have no children coming to our garden so I can, and occasionally do, use these here.