What is the ruling on ablution (wudu') when there is ointment (cream) on the affected areas of the hands, feet, and hair, and is it permissible to wipe over it (masah) given the harm caused by removing the ointment and reapplying it repeatedly?

"Whoever uses medicine on a limb of ablution and is harmed by its removal, it falls under the ruling of a splint (jabirah); he should wipe over it and not remove it. If he is harmed by wiping, he should place a bandage over it and wipe over that. It is not a condition to apply the medicine after a complete purification."