This is what I saw that made me think of the baling twine and/or netting wadded up in a pillow of plastic fencing material. With maybe some mashed up pop bottles with holes drilled in them for good measure.
Not sure if this is an advertising sponsor and I think there are limitations to providing links to non sponsors, but if the link gets removed just do a Google search for "artificial fish habitat fish feeder bag". This is where I got the idea. I would have figured this would TOO dense, but not according to this seller anyway.
fish feeder bag And yes, do take photos of whatever project you end up doing and post them. Also don't forget to tell us how it works out after a period of time. People read the old threads a lot (I'm one of them) to get ideas and it is always good when someone thought enough to go find their old post and present results after a year or two.
