Man that call gave me fits trying to figure out.
In a nutshell, here are a couple of tips to get you pointed in the right direction. First, condition the call once and start scratching on ONE spot on the call like you would any friction call. Let a bunch of the Aluminum build up and polish off the end of your striker until it is all silver. Wear down a spot on the call about one third inside of the edge toward the center in a crescent shape. Don't keep sanding the call. Sanding it will make it raspy and it needs to be smooth for the desired effect. (you'll see what I mean on the videos posted. Next, Form a bridge across your middle finger with THREE points of contact. 1. between your thumb and index finger 2. across the center of your middle finger 3. on your thumb. Now you have to really try to bend the striker to take all of the vibration out of it while you run the call. If you relax your grip it will get raspy and break the note like a regular yelp. If you are holding the striker very tightly it will give you the squeaky sound of a Kee Kee. It's still going to take some practice for you but this will solve your problem. I had it down in about two weeks and soon figured out that once I learned how to run it I could Kee Kee on almost any Glass or Aluminum call just about as good. Good luck!