Rope Tension = W /(cos a) Righting moment (*) = W * d
Where a= angle of the rope against the vertical (0 = vertical, 90° = horizontal) W is your weight d = horizontal distance between your center of mass and the hull (or the axis on which the boat rotates while righting )
No "a" on the second formula.. that is all the point of the discussion. Of course if a = 90° or close you cannot right the boat. That's probably what makes people skeptical
(*) That is the righting moment that you produce, not the total righting moment. It has to overcome the opposite moment produced by the mast, etc.