Swayamvara Parvathi Homam is performed mainly to attract Soulmate and also to resolve marital issues. The mantra is considered very powerful in this ritual.
Sage Agastya blessed Parvati with this mantra to help her attain Shiva as her consort.
One of the most powerful and Tantric worship as per ancient Rishis is the worship of Shakti, The Divine Mother. It is believed that the Divine Mother incarnated as Goddess Parvati in order to get married to Lord Shiva, and none other than the Mighty Lord Shiva himself gave the Swayamvara Parvati Mantra to Goddess Parvati. This is the same mantra that enables Goddess Parvati to reunite with her Divine Consort, Lord Shiva.