@catfluff Apparently they're high quality ice cream beads that are flash frozen cryogenically at -320°F. The reason they are not ubiquitous, is that in order to retain their look, feel and taste, they can never be exposed to temperatures above -40°F, thus precluding them from most store's "warmer" freezers and making shipping an expensive, time sensitive affair. That's why they are only offered as a specialty treat at high traffic venues that can absorb the shipping charges and justify the cost of running overclocked freezers full time.
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Seriously, never heard of them before in my life