Is it true that whoever sees a bad dream is prescribed to spit to his left three times while in the bathroom, then tell himself the dream therein so that its harm may dissipate?

Whoever sees a dream he dislikes should spit to his left three times while still in bed, seek refuge in Allah from the evil of what he saw, then turn over to his other side. He may also pray two rak'ahs. It is not prescribed for him to go to the bathroom to spit there, nor is it permissible for him to narrate the dream to anyone.