The World Federation One Stop Fiqh

Ruling 294

If before performing wuḍūʾ one knows that on some parts of the body on which wuḍūʾ is performed there is an obstruction for water to reach those parts, and after wuḍūʾ he doubts whether at the time of performing wuḍūʾ he made water reach those parts, his wuḍūʾ is valid.