Yes, Returning Curses does fuck up your enemies, especially in high repetitions of RAUM and SURYA (by high I mean 80 to 100, not 300, don't do things you can't handle yet).
Do BOTH parts.
Not to the extent of Black Magick, but it pushes any curse they put on you back onto themselves. This also removes a lot of spiritual garbage from past lifetimes. It also protects you in the future and tends to foil any attempt to attack you. One member using it consistently even escaped a serious car accident unscathed.
It additionally is extremely helpful when repeated past a certain point daily (40-80 day mark) because it can cleanse inadvertent harmful energy when attempting Black Magick workings (or unrelated to that, any undesirable mistake one can make).
Do not start it before you have opened your Chakras. And I don't advise starting the SURYA/RAUM part when the Sun is in Libra or Aquarius either, nor during a VoC Moon.