I knew someone at a bar who would use 4 foot lengths of PVC tubes. They’d fill the tubes and freeze them. The bottom half would be clear and the top half would have all of the impurities etc. (or maybe the other way?). The dirty half would get smashed for the well and the clear part would get polished into spheres.
Slowly.
Seriously.
All you need is to make the ice freeze slowly, and when it’s all frozen you just melt off the not clear part and you’ve got clear cubes.
You could also set your freezer to just below freezing and achieve similar results.
I knew someone at a bar who would use 4 foot lengths of PVC tubes. They’d fill the tubes and freeze them. The bottom half would be clear and the top half would have all of the impurities etc. (or maybe the other way?). The dirty half would get smashed for the well and the clear part would get polished into spheres.