In all my years in appliance repair I've never heard to put any part in boiling anything. We would sometimes take discontinued valve apart and soak parts in Cider vinegar for a couple of hours to clean. Once the crude was removed from the inside of the valve we'd check them threw several bench checks and most of the time they were good for a few more years. The hardest thing on a washer is setting for months without being used since water will dry up and leave a scale. the best way if you're going to not use the washer for months is blow out the water lines and valves.