Rav Shlomo Zalman Auerbach - One Last Laisheiv BaSuccah
There is a bigt machlokes among the poskim exactly for which Succah activity a person makes a Leishei BaSuccah. Technically it could be made for anything you do in the Succah since it is all a mitzva. In fact the Chayei Adam (147:15) holds that if you go into a Succah and have no plan to eat until the next time you leave, you make a Leisheiv BaSuccah. However we are noheg to make the Bracha only if we eat a KiBeitza of Mezonos.
However Rav Shlomo Zalman Auerbach (Halichos Shlomo 2:12:7) points out an exception to this rule. On Hoshana Rabba (in Eretz Yisroel) before Yom Tov starts we go into the Succah one last time to say good bye to this great mitzva (Rav Shlomo Zalman was very particular and emotional about people doing this). Since in this case you are going into the Succah purely for the sake of the mitzva, you can rely on the Chayei Adam and make a Leisheiv BaSuccah no matter what you eat, even if you don't eat a shiur of Mezonos.
Important Note: We bring this tshuvah as a starting point for discussion and not to convey any halacha. We try to convey the Tshuva to the best of our ability. We admit that our understanding may not be accurate. One should learn the tshuva to verify the accuracy of our interpretation. Please understand that this Tshuva may not be the final word on this topic. One should consult a Rav before drawing any conclusions.