I'm actually working on it. And, I'm using your thought about the disks with holes. -- Some of my work I do for a medium sized mechanical contractor with a full tin shop for HVAC. I spent a couple of hours messing with the cool tools today.
I don't have anything ready for photos yet, but here's what I started: It took a little while to figure out how to secure some disks inside a drip tip and it took even longer to figure out how many and what sized holes to drill... So, I didn't drill holes in the disks. I cut a cross into them. It requires two disks at minimum and so far, it restricts the airflow maybe too much, but that's a work in progress.
What I decided to do to secure them was to cut threads on the inside of the drip tip and I used some tweezers to spin them in to the threads. I figure a little piece of spring wire bent in to the shape of a lock nut will secure them and keep them separated.