Does the washing machine become impure when impure clothes are washed with pure ones in it, and can it be used to purify impure clothes only, while remaining pure?

If water flows over an impurity, as in automatic washing machines, then the impurity does not transfer to clean clothes or the interior of the washing machine unless the water separates having changed due to the impurity. If the water of the first rinse changes [due to the impurity], but then the water of the second rinse separates without having changed, then the impurity has been purified. It is more cautious to wash the impure parts of the clothes before placing them in the washing machine.