Is it obligatory to bury the tools used for washing the deceased (such as rags, loofahs, and soap) with the deceased in the grave, or to burn them, for fear of their use in acts of sorcery, and has anything been reported concerning this?

There is no evidence for the desirability of burying the tools used in washing the deceased. What is apparent is that this is not legislated, due to the waste of money involved. Rather, scholars have recommended burying what falls from the deceased's hair, nails, and body parts. Some jurists have recommended burying hair and nails so that sorcerers do not use them, and this applies specifically to the living.