The only way you can put chickens and beans together is with a few roast spuds and some nice gravy.
We have a number of allotment holders who use chickens to clear ground before they use the ground for planting.
They just create a pen using mesh barrier around the area they want to clear. The chickens are then released and within a day or two the whole area is stripped of anything that was green... they just devour everything in sight.
If the slugs are a big problem have a few evening sessions removing them by hand. It's amazing how a few removed on a regular basis will reduce the population.
My runner beans are about 10" tall at the moment, when I planted them I just add a few slug pellets a couple of feet away from them so as they get a chance to establish themselves without the slug. After a couple of weeks I just leave them to their own devices. A good tip is to make sure you start a few reserve runners in small pots, these can be used to replace any that get chewed in their early days.
Remember slug pellets attract slugs, they don't deter them ... so don't pile them next to your plants.
Another method I use is to surround the plants you want to protect with seaweed. The slugs don't seem to cross the seaweed whether it is wet or dried out .. I'm sure it's the salt content that puts them off.