First off, with any rag quilt, I first get it wet in the washer and spin it dry without agitating to keep from killing the pump on my machine. Then I put it in the dryer and clean the filter every 10 minutes or so just to get the worst of the strings and lint over with. I then go back and wash it in the washer and proceed normally. I know it takes a bit longer but it's that old ounce of prevention thing because.......
I also live with a well and septic system and cannot afford any problems. I've been filtering my washer drain water for years with an end of hose drain screen. They are cheap and you can pick them up really reasonably at Home Depot so nothing goes in the drain to stop up the works. You can also make your own if you choose to.