Yeah one does what I call "the claw" technique, where you kind of grip the huge lever housing with your first and middle fingers like a baseball or something, and hold down the actual lever with your palm. Terrible place to put any pressure on too, right there at the base of your palm, right where your literal carpal tunnel is....
I'm going to move it to the stem side of the handlebar for a more traditional approach while I look for a decent twist throttle. I see some really sweet aluminum ones on Amazon too actually, for amazingly low prices like $