Awesome zong, MaryJane!

I don't understand how you can't fit an ice cube in... that must be a fucking huge ice cube. This may be a stupid question, but you're trying to put the ice cubes in the tube, not where the slider goes, right?

Anyways, crushed iced works fine, but it might fall through easily so only crush it up to the point where it is just able to fall into the mouthpiece.