to answer this question more directly, --ignore-depends will allow you the dpkg command to succeed whereas normally it would fail. it does not alter package state; it does not record that you would prefer a package not to be installed.

the only alternative to doing this is to create a dummy facebook package that fulfills the dependency without doing anything, and then mark the version as 'fixed' so it wont receive upgrades.

really, my solution is a lot less involved than you might think.