As has been said above already, you can grab the wheel as firmly as you like, but it will not solve the problem reliably. The only thing that works is applying torque.
Too much torque, and the autosteering will get disabled. Too little, and you get nags and eventually kicked. It has to be the right amount.
Most of us here have got used to this and just rest one hand on the side of the steering wheel or grab the wheel with both hands, but asymmetrically, like one hand resting on the horizontal cross-bar, the other down.