It'll only help if the canards are greater than 1/2 the wing span.

A while back a guy with a very low aspect ratio biplane foamie tried to avoid the need for ailerons by using the elevator surfaces on his very large stabilizer that was about 1/2 span. The model was controllable but totally lacked the sort of aerobatic response he was after. He said something about it barely being trainer like and called it a dismal failure.

They do this on modern jet fighters where the stabilators are mounted well out from the center line but in most cases it's in addition to regular ailerons so I suspect it's as much for drag reduction as anything else.