The quintessences work in the lower and upper astral fields of the aura and therefore work on the more subtle fields of the aura.
Where the pomanders offer day to day protection the quintessences help to put us in touch with the energies of beings that are willing to assist mankind at this critical time of evolution on the planet.
The only way to reach these Beings is with a selfless heart and a willingness to open to something new. It does not in anyway mean that we have a "Master" in our pocket when using the quintessences.
Quintessences work on the subtle bodies. They invoke qualities of the archetypes that we would like to encourage within ourselves.