“Hosia’s themes are cleansing, offering, forgiveness, and magic. Her symbols are ritual tools. Hosia is the Greek Goddess who created all sacred rituals and ceremonies, Hosia oversees today’s rite of Thargelia and directs our magical energy toward successful manifestation.
Follow Greek tradition and leave Hosia an offering of fruit, bread or wheat to encourage her assistance. Next, consider creating a personal ritual for cleansing or forgiveness. Hosia will guide your hand in choosing words and actions suited to the working. Alternatively, take out your ritual tools and ask for Hosia’s blessing on them, saying:
‘Hosia, these are the tools of my hand, heart and spirit They symbolize the elements and the corners of creation Today I ask that you empower them for working magic and regulate their use for the greatest good May they always direct my energy in perfect love and trust So be it.’
In Greece, a scapegoat (often a criminal) was often identified to bear the sins for an entire community, then banished into the wilderness. A way to adapt this is by designing an image of something you need to banish, then ‘driving it away’ by putting it in the car and leaving it in a remote spot. As you turn away, ask Hosia to witness the rite and to empower your efforts for positive change.”
(Patricia Telesco, “365 Goddess: a daily guide to the magic and inspiration of the goddess”.)
While researching Hosia, I found some interesting things about the term hosia. I discovered that Hosia “is a word placed before the names of Goddesses. It means something like “holy” and “praise” and other things along the same lines.”  This could be the equivalent of the use of “Sri” in Hinduism, which is used as a title of veneration for deities (usually translated as “Holy”).
According to Karl Kerenyi as written by Daniel Browning, “cosmically, the gods form a boundary to human existence, at which humanity becomes aware of the difference between mortality and eternity. The victory of the gods is only possible because of their proximity to man. In this regard, certain protocols in ancient Greece had to be followed. Things and activities for the Greeks were either ‘hosia’ or ‘not-hosia.’
For example, in the Odyssey it is ‘not-hosia’ to call on the gods in the presence of corpses. Likewise, in the Hymn to Apollo, it is ‘not-hosia’ for mortals to use the horses tethered in the sacred precinct of Poseidon Hippios, because they are sacred animals. In reality these horses were cared for by priests. Poseidon’s horses were symbolic of the power behind the Sun, of the movement of time and the journey between cosmic shores. Poseidon’s trident was the center of their course: according to Robert Graves Poseidon planted his trident in the Moon and three fountains were born.
Kerenyi later points out that in Roman religion, the priest of Jupiter was not allowed to mount or ride any horse whatsoever — the horse being under the jurisdiction of the priest of Mars, the antagonistic deity of war. The priest of Mars sacrificed a horse on the October Horse day and thus was in intimate contact with the horse and its spirit.
For the Greeks, an animal sacrifice was a hosioter, and the death-dealer purified himself through the death-stroke. For the Bacchants of Euripides, the Hosia floated as a great Goddess on golden wings, a victory of life over death. She made sure that no rite of divine worship was neglected, and thus kept the divinities from exacting punishments. She made sure that both the Jupiter (Olympian) and Martian (Underworld) gods received worship in the form of holy observances. This kind of hosia is surely a precursor to the later Roman religion which was so concerned with Jupiter and Mars.
A characteristic of Greek religion is the ‘remoteness’ of the underworld domain, which is an ‘inner sanctum.’ The hosiotes aspired to Olympic heights, and for them the underworld domain was kept in the background, reinforcing the idea of the underworld as a ‘remote’ place. The regular world of the hosios was bright and clear, and the hosate priest did everything in his power to keep the hosia constantly flowing. One might add that in the everyday affairs of the hosios, hosia manifested itself as a simple ritual acknowledgement of the appearances of the Sun and the Moon — rarely did things get more esoteric than this.” 
That’s some pretty deep stuff. I’m by no means an expert or scholar, but after reading this and applying my soft-polytheistic point of views, it would seem to me that Hosia is not so much a “tangible” Goddess so to say (then again, what deity is tangible?) but more of an energy, or an Essence. It seems to me that Hosia could be compared to Shekinah (the manifestation of the Wisdom Goddess of the Kabbalah, the Hebrew Bible and Merkavah Mysticism ), the Holy Spirit , or even Sophia (the beginning, the source of wisdom, and keeper of the knowledge of all that is righteous and just ) in the Judeo-Christian religions. This could be a bit of a stretch, but Hosia could even, in my opinion, be compared to Shakti, the primordial cosmic energy that represents the dynamic forces that are thought to move through the entire universe in Hinduism.
This only furthers and confirms, for me at least, my deeply held soft-polytheistic spiritual views. With so many Goddesses all over the world sharing similar attributes and similar stories, truly, what else could it be? It is my personal belief that the different Goddesses are Essences of pure love, compassion, fertility, destruction, etc. – are energy and have the ability to manifest and act as messengers, helpers and catalysts. I often refer to Shakespeare’s quote, “What’s in a name? That which we call a rose by any other name would smell as sweet” to describe my views of the Goddess as She moves in and through the different cultures throughout this world. Her name may change, Her “face” may change, but She is still the same through and through.
I truly believe that the “Gods” were ancient man’s way to interpret and explain the world around him/her – giving the intangible forces around them tangible qualities and aspects in an attempt to understand and control Them. Their myths are but parables, tales and life lessons. In the bigger scheme of things, these Essences radiate from the Great Mother (the “Big Mama” if you will) who is Knowledge, Wisdom, Truth, and the Spark and driving force of Creation.
d’Este, Sorita & David Rankine. The Cosmic Shekinah, “The Book“.
Browning, Daniel. The Earthspace Discovery Website, “Kerenyi on Greek and Roman Religion“.
Goddessgift.com, “Sophia, Goddess of Wisdom“.
paleothea.com, “Greek Goddesses – H: Hosia“.
Harrison, Jane Ellen. Prolegomena to the study of Greek religion, “The Hosioi and Hosia“.