All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Washing with water takes place in both cases when water is poured on the whole body to reach every part, whether a Muslim does so before or after washing with soap or shampoo. This is what is required according to Sharee'ah. Passing water on the entire body with the intention of Ghusl (ritual bath) while there is soap or the like on the body does not affect the soundness of Ghusl. No doubt, it is better for the Muslim to take a separate bath using water only so as to follow the way of the Prophet in performing Ghusl, as well as other acts, such as following the proper sequence and beginning with right side, etc.
Allaah knows best.