Reciting Psalm 29 is very beneficial to keep away evil spirits. There are 7 verses in this psalm that begin with - "The voice of Hashem" (Kol Hashem) - which are said to humble the evil spirit.
Righteous people during their last moments of life will wash their hands and recite Psalm 29. Many Jewish communities recite this Psalm while returning "The Torah" to the Ark. It is therefore considered holy to recite Tehillim 29 when the soul is returning to G-d.
