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. We ask Allaah to exalt his mention as well as that of his family and all his companions.
There is no harm as you mentioned in adding hot water on which Ruqyah was not performed to water on which Ruqyah was performed. There is no harm also in performing Ghusl (a ritual bath) with it for three days instead of two days as it is not determined in Islamic Law to have Ruqyah for one day or two days. What is important is that Ruqyah is performed, but there is no harm in doing it more than once when necessary. You have to humble yourself to Allaah and put the matter in His Hands, as He is the One Who causes the means to yield results. Moreover, He is the One Who accepts the supplication of the person in difficulties when he asks Him, and removes the harm. So you should combine between Ruqyah and invoking Him in humbleness and submissiveness.
Allaah Knows best.