Will slugs and snails really refuse to touch copper?

I've got some seedling herbs outside that they keep having a go at. So I
was wondering if something like this:

https://www.amazon.co.uk/dp/B072MQFCM7

would actually work?

I'd prefer to keep toxic things like pellets away from foodstuffs plus I
don't want to needlessly kill slugs and snails - we have birds nesting
nearby that like eating them so it seems poor form to damage their food
chain.