Those tea balls don't work for pellets- the sludge slides through. But they work great for leaf hops! One thing to remember is that the hops have to be "loose" in the ball. You don't need a marble- they sink anyway. Jamming in a whole ounce won't give a very good effect. You're better off with 1/2 ounce or so, so that the hops are in contact with the beer. I use a couple of them in a keg, if I want to hop with a whole ounce.
Broken Leg Brewery
Giving beer a leg to stand on since 2006