Here is a boring video of my Seafoam cloud. Music added to extend your attention span.
My car has ~17k miles on it and I've had the Riss Racing OCC on it since about 500 miles. I emptied the can today and the crankcase side of the connector was saturated with oil, and the intake side was clean and dry (aka its working). Dumped about 30 ml of oil from the can after ~16k miles. If you dont already have a OCC, get one now if you care about engine life.
I recommend getting an oil change after doing Seafoam, so I have timed my treatment here a few days before I take my car into service.