Gliding instructors teach spinning all the time, cause we fly closer to the stall than anyone else and the rudder is very powerful. I used to get the student to turn normally easing back on the stick and as it slowed feed in rudder and see what happens. This had more likely teaching effect ,than yanking the glider into a high nose up stall and scaring the students. The K-13 was spun regularly from 1,000 feet after a good brief and Puchacz not below 1,500 feet. I would not let a student solo unless he recognised the stall/spin onset and could recover correctly.
Very important for every type of aircraft pilot to be able to recover from a spin. Read one of the last chapters in "Handling The Big Jets".