What is the correct way to purify clothes from urine splashes, and is wiping, reciting Bismillah, and the Tashahhud sufficient instead of washing them? What is the ruling on exaggerating in Istinja’ (cleaning oneself after relieving oneself) and washing inner garments and the private parts due to fear of Waswas (obsessive whispering), and what is the correct way to get rid of this Waswas?

A Muslim should not urinate while standing unless there is a necessity or need, and must be careful about impurity. If he is certain that impurity has afflicted his body or clothes, he must purify them. If he doubts whether it has afflicted them, sprinkling water (nadh) suffices. However, if something afflicts him and he doubts whether it is impure or pure, he should neither wash it nor sprinkle water on it, because the default state is purity. What the questioner does by wiping, saying "Bismillah" (in the name of Allah), and reciting the Tashahhud is incorrect. He must be wary of excessive doubt and scrupulosity (waswas) concerning purity. The remedy is to seek help through the remembrance of Allah, His supplication, seeking refuge from Satan, and disregarding doubts after being certain of purity.