Barks for guests

Zoe barks when people knock at the door or whatever.  Fine.  Then she will bark at them for a while... whether they pet her, ignore her, give her a treat or anything.  Sometimes she quiets down quickly (especially if it is a group of people coming over) but I find she is worst when one person comes over.  What can I do to keep her quiet?  She knows the word quiet but barks so loud she doesn't hear me and/or chooses barking over quiet :).  How can I perfect that so I always get her quiet?
 
I realize this is a dachshund trait but I would like to work on minimizing it as much as possible.