In a word? Yes.
The waterford is a bit that horses cannot work into a contact with. It is designed for horses that lean on the bit for support, specifically because it gives no support and requires the horse to support itself instead of depending on the rider.
When taking a contact with, for example, a simple jointed snaffle, the inside rein asks for the inside bend. The outside rein is firm, and in order to work properly into the bend, the horse must lower his head form the poll. In other words, the inside rein creates the bend and the outside rein controls the degree of flexion.
However, he cannot truly work on a contact if his backend is switched off.
With a waterford, this control over the flexion and bend is not possible, because the horse cannot accept the contact, since the links in his mouth are too mobile.
Sawing with your hands, or even sqeezing each rein in turn, gentle as this may be, encourages the horse to duck his head to escape discomfort. He is not seeking the contact, he is evading, although to the casual onlooker, the results seem the same. This is the reason a lot of people still do this.
Sawing with a waterford is even more severe, since the links run so easily through the mouth. It is the equivalent of you putting a bicycle chain in your mouth and pulling it from side to side. As it is impossible to work on the bit in a waterford, there is no valid reason why you would want to saw your hands anyway.
I personally hate waterfords. Take a look at sustainabledressage.net for a full explaination of bits, their actions and common reactions to them.
