Muslin bag is an effective, inexpensive alternative.
I've used the muslin bags with pellets and still get a lot of hop debris in the kettle. I don't know if it is because I occasionally hit it or somehow squeeze it while stirring the boiling wort. I still get good beer though.
+1 on the hop debris and good beer. It just doesn't matter unless it's plugging a plate chiller or other equipment.