He writtes in his book "Wild Stringdom"
To play sweep arpeggios correctly, you have to mute each note with the left hand immediately after picking it.
The best way to learn sweep arpeggios is to isolate the right-and left-handed techniques, master them separately, and then coordinate them.
c 2000 WARNER BROS. PUBLICATIONS
If you have a G major chord as the backing, and you sweep the same triad, you are not adding tension at all; you can sweep a G maj9 or any other extention of the triad, and then you will be adding tension.
Start slowly with three strings sweeps and after you master those, add sweeps that involve four, five and six strings.
Listen to great sweepers to learn from them, Paul Gilbert, Yngwie, etc.
Hope that helps a little.
