I live in the country in NC. My water is well

I also live in NC and experienced the same problems you describe. I tried all detergent additives along with bleach to no avail. After the rust and sediment started wrecking my appliances, I decided to install a water softener with a whole house sediment filter. It wasn't that expensive and I installed it all myself. The salt I use is Diamond Red Out salt. This not only softens the water, but completely got rid of the rust problem. Something you may consider. I've been rust free now for about 6 years.

For brighter, softer, stain-free clothes, add 1/2 cup Arm and Hammer® baking soda to your regular detergent in the wash cycle, then add 3/4 cup Heinz® white vinegar to the rinse. Soak really dingy clothes for ten minutes in the baking soda-detergent mix before washing in the hottest water fabric will accept. Vinegar smells should vanish after clothes have dried. Many online voters said that this worked best.