Pretty much. To strain the metaphor: if you have a pipe (conduit) it works if what you put in at one end comes out the other; if you have a filter and it passe

Pretty much. To strain the metaphor: if you have a pipe (conduit) it works if what you put in at one end comes out the other; if you have a filter and it passes what it's supposed to filter out, then it's a broken filter, eh?