Will it do any good to bury the ash and remaining bones, if left of someone who was cremated?

This issue is disputed in Jewish law and will depend on local custom or the decision of the local Rabbi. In general, if the cremation was done by order of the deceased, there is an inclination to prohibit burial, while if the cremation was done because of some other reason (government regulation, contagious diseases, wartime practices, etc.) burial of ashes and remains would be encouraged. However, I repeat that it is crucial to find out the local custom on this matter and to consult with a halachic authority about the particular circumstances of the deceased and the family.