I know this is long past, but I was looking for a electronic tin whistle or six hole flute I could use with my headset, and found this.

To make a quiet practice I blow across the window and not in the windway. or sometimes I will tap the finger holes but that isn't really good practice.

But thanks for the method of putting your lower lip on the windway, I had been blowing sideways and that's not really good technique either, I guess.

I think someone might want to make a smartphone app that simulates six hole fingering. I might try, I've made a few apps, but multitouch would be necessary and I haven't played with that.