My understanding has always been that one element of a Frise aileron is that when the aileron is deflected down (on the rising wing) that some airflow is directed from the underside of the wing to the top surface of the aileron, much like when a slotted trailing edge flap is extended.
Well put. Similar effect as a slotted flap.
In addition, the hinge point placement well aft of the aileron leading edge means that the Frise type aileron L/E will deflect downward into the relative wind when the trailing edge is deflected upward. Conversely, the leading edge is hidden in the wing T/E recess when the aileron T/E is deflected downward.
With a "normal" (non-Frise type) aileron, the wing with the upward deflecting aileron produces less total drag than the downward deflected aileron on the opposite wing. Both the Frise and differential deflection aileron arrangement are solutions intended to "recover" some of this lost drag in order to reduce the
difference in the amount of drag being produced by each wing. (adverse yaw) In that way, less rudder displacement will be required in order to maintain a neutral slip/skid condition when the ailerons are deflected. Additionally, the control force required will be reduced in roll. The airplane is "easier" to fly if it produces less adverse yaw. While airplanes so equipped can't make a chump fly like a champ, they
can help the passengers to maintain control over the disposition of their lunch! Every little bit helps I suppose.
If it's just for fun I'd rather fly a Cub.