Should have included a photo showing that. The "clips" holding the line are pieces of 1/2" ID rubber tubing slit lengthwise. The tubing has to be stiff enough to hold the line in place but flexible enough to pull off the line easily. When I made the first version I experimented with scraps of different types of tubing I had laying around. The black rubber tubing shown in the photo seemed to be the best compromise. I believe it was a section of old dishwasher drain hose.
The "clips" are attached to the holder with flat head screws. The two "clips" at the bottom of the "U" are screwed directly into the CPVC. The two "clips" at the ends of the "U" are screwed into a short length of 1/2" dowel that I glued into, and sets flush with, the end of the CPVC tubing.