For spiritual intentions, Ruda or Rue is best known to use for cleansing from envy, bad vibes, and bad luck.
If smudging for spiritual, energetic, and negativity clearing purposes. Remove animals or people from the room. To cleanse with Ruda Rue is best burnt on charcoal tablet discs. Once the charcoal is lit you can spoon or sprinkle the herb on in small amounts. The heat from the charcoal causes the herb to slowly burn thus producing the desired smoke without a flame. Go from room to room into all the corners with intention. Make sure to open your windows!
Keep in mind: Burning smudge is a sacred religious practice. Treat the ritual with respect.