According to this Islamic ruling and fatwa, the common practice of giving extra baths like janabah غسل to the deceased is not correct. Only the غسل میت (funeral bath) is sufficient.

Islamic scholars explain that the funeral غسل is enough, and there is no need to perform additional غسل for impurity. غسل میت does not require intention like other types of غسل, and it alone fulfills the requirement.

This fatwa clearly shows that adding extra غسل is unnecessary, and one should follow the correct Islamic ruling by performing only the غسل میت.