How to correct a roll due to turbulence? I fly a Piper Cherokee 180 (PA-28-180) in an area that has frequent turbulence. When turbulence causes the aircraft to roll to one side I usually try to correct by using aileron and rudder in the opposite direction of the roll.

However my flight instructor says that I should use rudder only to correct for the roll. I can get the wings level by using only rudder but it seems to me that using aileron and rudder would be the most effective method. Can someone please explain to me why I should use only rudder in this instance?
Your instructor needs some... instruction.  Inducing roll using rudder alone is something you do when you are right on the edge of a stall because a downgoing aileron can potentially induce a stall when right on the edge.   In a normal climb, using rudder alone is totally nuts.  

Apply only the rudder required to keep the ball centered with the application of whatever aileron is necessary.   If you needed all the roll power you can possibly get, you would apply full aileron and full rudder to use the resulting skidding to increase the roll rate.