Cock cages have their place, but if they had tied her cock correctly, with her balls wrapped tightly in rope so that they were separated from her cock, then rope applied around the base of her cock and wrapped around tightly, covering her cock from its base to the head, so only the head was left exposed, then she would have no way to cum. The cum would be locked in her balls. If I got you in that position I am sure you would become more compliant and co-operative.
And the slightest tap to cock or balls would keep you in line if you failed to follow directions. 🙂