Is it permissible to wash the deceased if most of their bones are stained with blood as a result of a painful death?

If ghusl is not possible, a Muslim should perform tayammum, due to the generality of Allah's saying: (So fear Allah as much as you are able), and because Allah legislated tayammum for purification from the two impurities when water is unavailable, or one is unable to use it, or is harmed by it.