Yes. But, you're still putting in media that will trap solids were you won't have many cleaners, which means you will have to do most of the cleaning of the floss, and frequently to prevent it from becoming encrusted with critters-and trapping and killing anything that spawned in the tank. You'd be better off putting the filter in the system, and then running it with no media, for water current. This way, if something happened and you NEEDED to run chemical or mechanical media, it would be easy to do so, but not impact the system otherwise.
I think I have a sponge that's just been floating in one of my sumps--I'll try getting a picture of it to show you how encrusted them become.