Does a towel used to dry a ritually pure private part after purification from urine become impure, and is it necessary to wash it before reusing it?

If the questioner wipes with a towel after washing away impurities and drying the area, then the towel remains pure and it is permissible to use it again without washing; because its contact with the private parts after their purification does not render it impure, and the basic principle regarding things is purity. It is advised to disregard obsessive thoughts and not pay attention to them.