Yes, once the engine and airplane are set up to allow that to happen, that is how you do it. But some engines do (or did) come out of the box with the throttle stop screw set so that the servo (or your finger or anything) could not move the throttle barrel all the way closed. So you could wiggle the stick or the trim lever all you wanted, all you'd get is a stalled servo, the engine would not cut off or idle below a certain point because the carb would not close enough.