Copying clips from projects don't show in browser so can't media-manage it

Hi
having a large project/sequence in which i have to drop/cpoy many clips from other projects, at the end I don't see all these "outside" clips in the browser, so at the end, when I wish to clear and media-manage it, in order to have all the clips used copied to an only specific folder, i'm not able to do that, cause media manager only affects to what's in the main project browser..and mine is almost empty while my sequence keeps tons of clips..
any solution for archiving my project and putting everything in one place?