Product review (5 stars): Plumber Bill Saver
I have found these screens to be an economical way to avoid plumbing bill/s to clean soap scum build up, lint etc from my water/sewer pipes.  I attach the filters to my washing machine water discharge hose.  I use a car radiator hose worm clamp but you can use the plastic ties included with the filters (I just found it easier and quicker to use the worm clamp).  The screens fill up with excess soap scum and lint.  I replace when they appear to be loaded with lint...ever leave a tissue in your trouser pocket?...big mess but the filters keep the paper out of your pipes and drain tubs when the washer discharges the rinse water.  Since applying these filters about five years ago I have not had to call a plumber in all that time to "snake out" the pipes.