What is the ruling on doubt regarding the the removal of impurity or the existence of a barrier preventing water from reaching the hands, when an individual suffering from obsessive compulsive disorder (waswas) washes their hands?

If you wash your hand from impurity, do not pay attention to it, and do not rule that anything prevents water from reaching [the skin] except with certainty, for rulings are not established by doubt. Dismiss these thoughts you are experiencing, and we advise you to adhere to supplication and humility, and to distract yourself from these whisperings. It is recommended to consult a trusted psychiatrist.