Yes I swear by it now made my ex racer so much lightly in the hand, he took the bit more with it, I now won't ride him without putting a little bit in the corners of his mouth
I have been using it when I ride my WB - he can go very dead in the mouth - it definitley makes him mouth his bit more and I have been sure it is making a difference. I had my first lesson last week and my RI commented on how much softer he was in the mouth, mouthing the bit etc - she had no idea I was using it but when I told her she said keep using it as it making a difference