I don't think I remember a DI in any of the Alaska ports (probably because they are US ports). In any case I wouldn't waste my time with the charms. They are just a marketing gimmick to get you to go into a DI store and talk to a sales person... who of course puts the hard sell on you to buy some real jewelery. Sorry but I have better things to do with my time when in a port than to go to a jewelery store.
If the cruise lines were not getting significant kickbacks from these "preferred stores" they wouldn't push them onto everyone.
Carnival Cruise Lines:
Fantasy 90, Celebration 95, Victory 05, Conquest 05, Spirit 6/06, Freedom 6/08, Holiday 7/08, Victory 6/09, Valor 9/09, Dream 6/10, Splendor 8/10,Conquest 8/11,Magic 11/11,Triumph 4/12,Spirit 7/12,Freedom 11/12, Triumph 2/13 - The fire cruise
NCL Dream October 2006, RCCL Mariner OTS June 2007