Ice cubes that cool and do not water down
The plastic things that contain a coolant are far too expensive to stock in sufficient quantities. 2. Do not keep cool for long, because they are thawed quickly. And 3. may the gods know how dense the plastic balls are or how unhealthy the coolant is, that eventually spread out into the glass. I do not even trust them half as far as I could throw them.
I simply use the commercial ice-ball bags, but fill them with water instead of water with the preferred drink (no matter what). For carbonated soft drinks, however, I first pour the drink into a liter measure, stir out the carbon dioxide, and then pour it into the ice ball bags so that they do not burst.
So even in midsummer, I always have plenty of ice balls for nicely chilled drinks in low-priced fashion, without them watering down.
