Yes. You can use spoilers to roll a plane if you lift only the side you wish to bank towards. I believe that is how the B-2 bomber does it. They function as spoilerons if triggered independantly (and proportionally vs. up or not) and can be thought of as 100% aileron differential. Note that you'll also be setting up some odd lift & drag differences in the wings and you'll probably need to compensate with rudder. I wouldn't be surprised some models (with non-dihedral symmetrical wings) might get some adverse yaw and dutch roll on you.

I have several models set to raise the ailerons on a slider switch to act as spoilers. It kills lift and allows the model to settle at a steeper angle. In this case they function both as ailerons and spoilers.

Flaperons are just the opposite - the ailerons can be mixed to drop together.