As 411A said, getting into a 'rudder lock' situation can ruin your day. I think there was some kind of modification that eliminated that possibility, but then it has been a really long time since I flew a DC-3.
However, I can say I never tried to make a turn in a DC-3 with just the rudder, never saw any reason to actually.
Now you could steer the DC-3 on the runway with just the alerions, now that was fun. Well, as long as you did not have a strong crosswind.