Does the use of a hair styling cream made of coconut and beeswax prevent the validity of ghusl and wudu, and is it permissible to wash the hair again with soap half an hour after ghusl if a greasy residue of the cream is found on the hair?

Whether a cream prevents water from reaching the hair or skin cannot be determined except by seeing or touching it. If you wash your hair with water, even after some time has passed since washing your body, the state of Janabah (ritual impurity) is lifted, and nothing further is required of you. This is because performing the ghusl (ritual bath) for Janabah consecutively (al-muwalat) is a Sunnah and not obligatory according to the majority of scholars, as mentioned by Ibn Qudamah.