Thanks man.
I was trying to think of alternatives to cones a couple of years ago, but there aren't many options that are practical. Old detergent bottles, milk jugs, etc. with a little bit of water or sand in them to give them a bit of heft could work, but they won't stack together like cones do. There might be a workable solution, but I wasn't able to come up with one before I started thinking about something else. lol...