I also saw that study and was very intrigued, especially with this blurb:
Although the levels of CBD seen in the plasma of patients receiving Sativex are below (73) the CBD doses (= lower micromolar range) that exerted the most robust effects in our studies, such doses could easily be achieved after topical CBD application, using appropriate vehicles already used in current standard acne management. Due to its high lipophilicity, CBD is expected to preferentially enter the skin via the transfollicular route and to accumulate in the sebaceous gland (74, 75).
A couple months ago, I tried applying the "Wellbe" brand cbd oil to the left side of my face for a few weeks, but there was no decrease in sebum or acne.
I've been debating whether to try a higher concentration cbd oil, but these types of cbd oils can very expensive.