Those are the only kind I can use. I can't make a single peep out of a mouth reed. The calls I use are kind of different. One is referred to as a "bite and blow" call and that's how it works. You bite on the end and blow through it and how hard you bite dictates the sound. Bite harder for higher pitch and let off to get lower pitches.
Another call that I use a lot and like a lot is a true open reed and I have to get it wet to make it work right. I lick the reed before using it. Then vary the pressure on it to vary the tone. And I have to use it with the reed down. I think you can use it the other way but if I use it right side up it vibrates my lip and makes me sneeze. Kind of an extra bonus.