Just found this in NS.
https://www.newscientist.com/article/mg25333760-900-rory-mc-donnell-interview-the-slug-hunter-with-a-strange-new-weapon/I'm interested because a friend had great success with a few ml of beer in bottles left on their sides.
The downside was he had to buy the beer, and of course it got weaker every day as the alcohol evaporated.
I'm not prepared to waste drinkable beer on slugs, so I tried using the lees I throw away after brewing (or home-made fruit juice that's fermented in the fridge - often delicious) - but for some reason the slugs weren't interested.
Using bread dough makes a lot of sense - especially in terms of economics - it's still fermenting while waiting for customers, and the flour will maintain the attraction too (and I suspect stale bread with a small dose of lees will work just as well - might even try adding cardboard - they seem to love it).
Can't wait to try it.
Cheers.