Here are my KS9’s with DIY silicone earmolds and a picture of one in my ear.
Per the instructions I use a dome on the receiver to protect the outlet tube when doing the molding. I roll the mixed silicone out into a long thin rod and then wind it around the receiver before putting it in my ear.
I had bad occlusion effects with my left ear and mild effects in my right ear. The grooves you see in the photo are vents that I made to fix the occlusion effects. I used a razor blade to cut the grooves. The instructions suggested using a small file for this.
I paid something like $30 for the silicone kit and have made 5 or 6 sets of earmolds for various reasons. I probably have enough left for several more sets if needed.