sam,
not sure if it will work for you. for my kids, they are not allow to bring pacifier out of the house after they reach 7-9 months old. can't remember the exact month. pacifier can only be used at home. when if they have to nap outside, it will be without it unless i go overseas. even overseas, it will be used only in hotel room.
of course there is resistence in the beginning, do it consistently and they will get the idea. now my #2 sees any baby having pacifier outside, she will complain to me and say baby eat tutu, cannot eat tutu, must keep.