Here's what I do a couple of times a day - I put my fingers over the end of the venturi tubing to stop air from entering the pumps. That makes the water level rise in the skimmer and pushes the dirty foam up and into the collection cup. If you do this a couple of times a day, it gathers skimmate and the neck has less gunk accumulation.
Of course, cleaning the cup and neck daily is your better option, imho.
