What is the ruling on doubting the transfer of impurity from a child's urine after washing clothes by hand, and doubting the touching of hair and ear?

The cure for obsessive thoughts is to ignore them and not pay them any mind. The transfer of impurity is not determined by mere doubt, and the default state of a thing is purity. It is not necessary to wash all clothes; rather, it suffices to pour water over the impure spot. Submerging clothes in water is sufficient to purify them from impurity. There is no need for these obsessive thoughts, and one must rule everything about which there is doubt regarding its impurity as pure. That which is certainly impure is purified by submerging it in water.