The first method is relaxed stretches. This method works very slowly. On the top of that risks of injury rise, as the muscles relax. This takes away from the readiness of carrying heavy load.
The second method involves simply pushing through. In other words, doing the windmill many times over, till eventually something gives and the person becomes more flexible.
Zaichik Stretching techniques take different approach. Each muscle is taken apart. (Hamstrings, lower adductors, abductors, etc.) Each is quickly targeted one by one. This allows to find where the tightness is and focus in on it. Because of Zaichik Stretching action vs action technique, the pain of stretch reflex is avoided. This allows for very fast flexibility gains.
Together with the flexibility exercise, skill specific strength exercises are shown. This allows to develop strength in deep ranges and direct it into the skill right away. Many of the students are able to go deeper into the windmill and come up strong and more stable after just one session