Huh, okay. So, I'm pretty much on the right track, just need to be a bit more thorough.
A jeweler's ultrasonic cleaner? How much are they and where can I get one?
And as for backflushing-you know, I've been trying that too, but when I block off the front end and spray, nothing happens. Nothing bubbles up in the cup. It just acts as if you're blocking off the airflow again. I assume the needle and the tip have to be off, right?
I am relieved that at least I'm pretty much cleaning it right, just not ENOUGH, maybe. Thanks all again for your help. I love all the knowledge you can gain on this site-only posted about ten times and I already don't feel like Homer Simpson with a watercolor set anymore LOL.