I found this recipe on the net last night.

CORNED BEEF

INGREDIENTS
corned beef
1.25lt bottle ginger beer
1 onion quatered
1tbsp golden syrup (optional)

METHOD
place corned beef in slow cooker, place in onion and golden syrup(optional), pour over ginger beer.
Cook on low 8-10 hours
or cook on high 4-5 hours.