It might also be noted that you can soak the herbs in isopropyl alcohol for a few hours (I left it overnight). Then drain off the alcohol and let much of the rest evaporate - once you have a thick sludge in the bowl, mix in the carrier oil of your choice (I use Jojoba).

I used this method to extract the scent of this rich pipe tobacco called 'Black Bear' which has a rich, pungent, currant-y smell to it. It makes a great perfume on it's own, or as the bottom note of a blend.