I think the spell is against the Buddha's intention, so it's best to choose a date to be cremated. I remember the temple of the older generation said that amulets need to be placed on the holy table for three days and then cremated.
Religious integration was not put forward by Buddha, but by Kong Jing, an old monk in modern times. Previously, there were so-called great fusion religions in the late Qing Dynasty and the early Republic of China, but they were all classified as cults, such as Yiguan Road. Therefore, this statement cannot be the basis of Buddhism.