“Activator” is a particular chiropractic technique that utilizes a spring-loaded “gun” to make an adjustment. Vert is taking the “gun” aspect a little too far in this cartoon.
As a side note: I too reach for the Activator as one of the chiropractic techniques I ultilize. By the third year in practice, I began to see the wisdom in wearing the adjusting device in a holster like Vert — only I don’t double up. 🙂