"RicodJour" wrote:

How about a septic system? Synthetic fibers don't break down in a
septic tank or leaching field. They just accumulate it and block the
drainage and they you have an expensive problem.

Non-soluable material in a septic tank either floats or sinks. The tank is
designed to draw from the liquids in the center of the tank. Any fiber would get
pumped out of the tank with all the sludge during the normal cleanout every
couple of years.