Randy, That was one of my worries as well. It seems that if you run it often enough - "gunk" never really has a chance to build up thick on the inside of the neck. I have mine set on my Apex to cycle for 1min twice daily.
IME, the cleaner the neck is the smoother the transition for gunk to go from the neck, to the cup.
My other concern was killing the foam head inside the neck, but it has very little impact. When I feed any frozen food (daily) it destroys the foam head compared to the swabbie.
Great reviews guys. Do you guys empty out the cup or do you have it drain into a waste container?
Any one use one for Super Reef Octopus?
And how did you like it?
I got mines and I also uped to send in my lid so that they woukd do a retrofit to my skimmers origial lid. It's great and easier to take out with the retro fit. +1 on great customer service.