Yes, as a passenger nipper in a Blanik and T-21 at Nakuru, Kenya circa 1970-72. Wondered if you might have been there too. The club also had a Swallow, I can't recall other club gliders, but a number of Germans visited in '72 with ASW-17s and other exotica, and Walter Neubert set a world distance record (300k triangle I think). There was an air to air pic of one of them soaring close to the peak of Mount Kenya.
We kids mostly rode in the back of the tow car and helped retrieve the cable, or sometimes flew in the back of the Citabria.
I was only 8, but I recall it as great fun!