What is the ruling on rubbing fingers during ablution when there is dead skin on them, and is it sufficient to wash their outer surface without their inner surface if a piece of nail obstructs the water from reaching it?

The question has been answered previously. The missing phrase can be understood from the context, and one must get rid of obsessive thoughts, as ablution is easy and convenient. For ablution or ritual bath to be valid, it is a condition to remove anything that prevents water from reaching the limb. Complete cleanliness is not a condition; rather, it is sufficient for water to reach the skin, and for one to predominantly believe that it has. A small amount of dirt under the nail or in the nose does not cause harm, and it is not obligatory to remove dead skin if it causes pain.