And try this:
Select a bright trumpet voice. Using the default assignments, turn Live Control 1 to around 9 o'clock and Live Control 2 to around 3 o'clock. With a little adjustment either way, you'll end up with a muted trumpet that's better than the preset voice. (You can create muted trombone, flugelhorn, cornet etc too).
Now waggle the Mod Wheel and listen to it act as a plunge mute, giving a wha-wha effect.
Very handy!