I have worked with a 5 year old boy with Apraxia for 3 years. Each new sound took a long time to develop but the /k/ remained elusive. The ASHA Leader toothbrush cover (May 2018) sparked an “aha moment” for me!
I found a super hero toothbrush at the drugstore which captured this client’s imagination. With cueing, he holds his tongue tip down with the back of the toothbrush. Now, he can consistently produce a series of accurate /k/ sounds. I call it “magic”. He calls it “Special Super Heroes.”