The plank or stone [or other such surfaces] on which a corpse is given ghusl, and the cloth with which the private parts of a corpse are covered, and the hands of the person who gives ghusl – all of these things that usually come into contact with the corpse and the water that is poured on the corpse – become pure once the ghusl is complete.
However, based on obligatory precaution, the clothing and body of the person who gives ghusl and other instruments used for giving ghusl do not become pure by subsequence and need to be washed separately.