OK, beer can be stale so it doesn’t have to be fresh. You can collect leftovers from visitors beer if they do drink beer at your place.
I find that a coffee cup with dregs in it of coffee/milk/sugar, will attract slugs and snails.
Remember that snails can float to the sides and climb out.. liquid traps like beer etc, will drown slugs but not snails.
The red snail bait made by multigrow(from memory) is chelated iron so isn’t toxic to pets or children and is a soil improver.
Catching snails and dropping them in a bucket of salt is more effective than trying to get them to drown in beer.
The most effective way to rid yourself of the common garden snails is to remove plants that encourage them such as the many bulbs. Alternatively, if you want to keep your Aggies, then check them regularly and hand remove all the snails. Clean places where snails might hibernate regularly. Failing all of that, move to a desert. I found that simply by not watering other than by trickling hose combined with the extended drought, I have not a single garden snail left. Just white shells. This is in a garden that in the eighties, my daughter could pick 300 snails up in a sq m.
My problem now relates to slugs and the imported white Italian snail, which is tougher than your average snail.