It would never be cool to hold the bar while doing fast or difficult picking techniques , but for easy picking while holding the bar without accidently changing the pitch , I use finger picking motion (only move the thumb and index to move the pick) and hold the bar very loosely.
Check out Steve Vai's G3 solo before "For the Love of God" ... He use the same way I've explained at the end of it (or let's say , I use the same way he does ) .
