MGTrumpet - sounds a very familiar concept. I frequently use mouthpieces buzzing for flow exercises, but have found that many students find the difference between mouthpiece alone and the mouthpiece plus trumpet is enough to cause them problems.
I think this is why my ex-teacher was suggesting the soprano trombone - the feel is virtually the same as when using the trumpet.
Once you can understand the difference in feeling then the mouthpiece alone is much easier to carry around.
Something I enjoy working on with younger students is stealth learning - we do mouthpiece buzzing, seeing how smooth they can get it and how wide a siren they can play without any gaps appearing in the sound. They don't need to know that this is good for them. They don't need to know why it is good for them. They find it great fun - the fact that it is a good thing for them to do is a nice little bonus
