A Pure Organic Product. Tea Tree Hydrosol. Hydrosol is a chemistry term meaning 'water solution'. Hydrosols are the condensate water co-produced during steam or water distillation of plant material for therapeutic purposes. This nasal spray is a mild solution to decongest and clean the nasal passages aiding with colds and flu or for allergy sufferers. Antiseptic health for your nose and throat. Comes in a 20ml nasal spray bottle.