Sheikh Fawzān – may Allāh preserve him – says that performing wuḍū well means to perform it by doing all of the parts thoroughly, making sure that no part is left dry: The Prophet (May Allāh praise him and Peace be upon him) saw a man leave his toe nail. So, he said to the man, “Go back and do your wuḍū well”. [Ṣaḥīḥ Muslim (243)].