Thanks for the blog on how you did your pour.  Makes sense. 

I just noticed another shape that I think is cool. 



I could see stacking the cholla horizontally so that just the ends are showing once turned -- each one probably looking a little different in cross section.  You could cut shorter chunks so that they can be stacked in a ring around the perimeter of the cup.  Might a good use of some smaller cutoffs.  

--Nathan, TX. Hire the lazy man. He may not do as much work but that's because he will find a better way.