Thats a tough one, if you have people coming around & they might bring booze with them. If you really can't tell them, there are really two options. You can cancel the dinner/ party or maybe try to make it into something like "Hey, why don't we have a dinner once without any booze and let's see how it goes" - either way I would not have any booze floating around the house. The temptation is what got us here in a first place.
Good luck!