unyquity
Actually, when we want herbs to absorb into the skin, a "spray" is not NEARLY as effective as a fomentation (a cloth soaked in a very warm, strong tea, applied with warmth/heat to open the pores/follicles and 'drive in' the herb/s). This is particularly important for issues such as folliculitis (where the source of the infection is 'several layers deep').
With an herbal tea or tincture sprayed onto the skin, the water or alcohol is going to evaporate quickly, leaving the residue on the top of the skin. In order for an 'herbal spray' to be driven deeply into the lower layers of the skin, one would need it to be mixed with something like DMSO (a chemical solvent) to 'drive it in' (or some other chemical, or an essential oil).
I realize that we can blend essential oils with water/alcohol, but I do not know the 'persnickety details' of how it's best accomplished. Hence, I don't know if once essential oil is applied to skin, if it acts as a barrier to alcohol/water, or a 'carrier'...nor do I know if the type of essential oil matters.
Maybe Water_01 knows something about the specifics of either mixing essential oils & water/alcohol, or the effect if they're applied before a fomentation or other alcohol/water herbal blend...and will chime in.
'Wish I had more to share - I always use fomentations when I need 'topical applications'.
Uny