Is it permissible to wash impure clothes with pure clothes in an automatic washing machine, and do they become purified by that? And do all clothes become impure if traces of impurity remain after washing?

If water comes into contact with an impurity (najasa), it does not become impure unless it separates from it having changed [in color, smell, or taste] by it. If it separates from it without having changed by it, then neither its impurity nor the impurity of the clothes it touched is ruled. There is an opinion that considers the water impure if it separates before the impurity is purified, even if it has not changed. The more cautious and conscience-clearing approach is to wash the impure areas before mixing the impure clothes with the pure ones.